On Mon, 11 Jul 2011 11:47:31 +0100, Invisible wrote:

>> Firefox does not ship with AdBlock Pro installed.  People download it,
>> install it, and use it successfully.  I happen to be one of those
>> people.
>>
>> You, instead, have assumed "it can't possibly work" and so haven't even
>> tried it.
> 
> Before we get too far into this, I would like to re-emphasize what I
> actually said:
> 
> I said I had never bothered trying such software under the /assumption/
> that it won't work properly. I said that it looks intractably difficult.
> Then again, so does writing non-trivial software using something as
> primitive as C, and apparently people manage to do that.
> 
> In short, I would be surprised if ad-blocking technology can work. Not
> astonished, but definitely surprised.

Prepare yourself to be surprised, then. ;)

It works pretty well.  Not 100%, but IME better than 90%.

>> You're declaring failure because 1 message in "n" (for sufficiently
>> large values of 'n') gets through.  Fact is, spam filters aren't
>> supposed to block all spam.  They're supposed to reduce it, and for
>> most people, they do the job properly.
> 
> In my book, if I use a spam filter and still receive unacceptable
> quantities of spam, or have unacceptable quantities of genuine mail
> filtered, then the filter is "not working". I agree that 100% filtration
> would be almost impossible, but (for example) 3% filtration is useless.

We can agree on that last sentence.  Now, using various spam filtering 
technologies myself over the years, I've seen some good ones, and some 
excellent ones.

3% filtration is not what I've seen with any solution that I've used.

>> Have you tried something like Spamassassin?
> 
> Nope. If fact, I've never actually installed spam filtering technology
> myself. I've only had it forced upon me by whoever is operating the mail
> server.

One of the benefits of using something like fetchmail to pull from an 
external server to your own is that you can do this.  I use fetchmail to 
pull from my Earthlink account (which has its own spam filtering 
enabled), and fetchmail delivers to my local mailbox after running it 
through spamassassin to catch the ones that got through the Earthlink 
filters.

>> And yes, you do work in an industry where the normal triggers for spam
>> might actually be legitimate business communications.
> 
> Quite. This has no bearing on the spam filter at home being similarly
> useless, however.

No, that has to do with incompetence at your mail provider or an improper 
configuration on your account.  Since I don't know what they use, I 
couldn't comment on that.

>> That doesn't mean spam filters are useless.
>>
>> You'll note that I didn't say *all* spam filters were wonderful and
>> flawless.  I said that spam filtering generally works well.
> 
> Even I didn't say that *all* spam filters are useless. I merely said
> that I've yet to see one that isn't. (I even qualified it by saying I
> haven't seen all that many.)

Fair enough.  You seemed to be implying it in your original post, but re-
reading it, I see that I inferred something that perhaps wasn't there.

Jim

Post a reply to this message

On 7/11/2011 2:29, Invisible wrote:
> Ah yes, the argumentum ad populum. You realise that *millions* of people use
> Internet Explorer, right? So that *must* mean it's the best web browser. :-P

No, it means the web browser works. What you're missing is the fact that 
people complain they have to do something special to make IE6 work. But 
until very recently, everyone *was* doing something special to make IE6 
work, and hence IE6 works.

-- 
Darren New, San Diego CA, USA (PST)
   "Coding without comments is like
    driving without turn signals."

Post a reply to this message

On 11-7-2011 11:10, Jim Henderson wrote:

> Which planet are you on again? ;)

Andy is from Milton Keynes. I am not sure if that is a whole planet or 
tha last village populated by irreducible Celts that still resists to 
the Google invaders.

Post a reply to this message

On Mon, 11 Jul 2011 18:03:44 +0200, andrel wrote:

> On 11-7-2011 11:10, Jim Henderson wrote:
> 
>> Which planet are you on again? ;)
> 
> Andy is from Milton Keynes. I am not sure if that is a whole planet or
> tha last village populated by irreducible Celts that still resists to
> the Google invaders.

LOL

Post a reply to this message

>> AdBlock actualy prevent the ads from even starting to load.
>> It's realy a "Can't live without" addon.
>
> I've never installed this or any similar system under the assumption
> that it is almost guaranteed not to work.
>
> Designing a mere algorithm which can determine, with 100% accuracy, the
> difference between vital content and useless advertising garbage looks
> almost intractably difficult. Thus, the result would almost certainly be
> a system which either fails to block the majority of ads, or blocks the
> majority of useful content. (Or possibly both, at the same time.)
>
> In other news, I have yet to see a spam filter which actually filters
> out spam and nothing else. (Then again, I haven't searched extensively
> for one...)

The spam filter on Thunderbird is prety good and becomes beter with 
time. It literaly learn what is spam and what is not.

The spam filter on GMail is also exedingly good and effecient.

It's been a LOOONG time the last time ether of those missed a spam or 
mistoke legitimate mail for spam.


Adblock use a black/white list aproach. The black list contains an 
extensive list of known add servers.
If it misses some adds, you can right click it and set it to be blocked.
It keeps a log of blocked elements.


Alain

Post a reply to this message

Invisible <voi### [at] devnull> wrote:
> I've never installed this or any similar system under the assumption 
> that it is almost guaranteed not to work.

  Just try it. You'll be pleasantly surprised.

> Designing a mere algorithm which can determine, with 100% accuracy, the 
> difference between vital content and useless advertising garbage looks 
> almost intractably difficult. Thus, the result would almost certainly be 
> a system which either fails to block the majority of ads, or blocks the 
> majority of useful content. (Or possibly both, at the same time.)

  It doesn't need to do smart filtering. It only needs a blacklist. Said
list updates automatically.

-- 
                                                          - Warp

Post a reply to this message

On 12/07/2011 07:15 AM, Warp wrote:
> Invisible<voi### [at] devnull>  wrote:
>> I've never installed this or any similar system under the assumption
>> that it is almost guaranteed not to work.
>
>    Just try it. You'll be pleasantly surprised.

Well, yes, there is that...

(In a stunning turn of events, I actually have some work to do today. 
Yeah, I know. Imagine that...)

>    It doesn't need to do smart filtering. It only needs a blacklist. Said
> list updates automatically.

I don't get how that can work.

If it blacklists the server IP addresses, all you need to do is copy the 
ads to another server and the blacklist is defeated. As a bonus, if you 
put the ads on the same server as the genuine content, then you *can't* 
blacklist the server or you'll be blocking genuine content.

If it blacklists the MD5 hash of the ad files, just take each image and 
change 1 pixel. The MD5 hash is now completely different, but the ad 
still works just as well.

If it blacklists the file /name/, it's trivial to rename it.

If it blacklists the code fragments used to link to the adverts, just 
make any trivial cosmetic change to the code and you've defeated the 
blacklist.

All of this on top of the fact that blacklists are generally ineffective 
anyway. (If you filter anything - spam, malware, adverts, whatever - 
based on a blacklist, then that blacklist will always be out of date and 
you need an army of people to constantly update it for you.)

Post a reply to this message

Invisible <voi### [at] devnull> wrote:
> If it blacklists the server IP addresses, all you need to do is copy the 
> ads to another server and the blacklist is defeated. As a bonus, if you 
> put the ads on the same server as the genuine content, then you *can't* 
> blacklist the server or you'll be blocking genuine content.

  The vast majority of ads come from external URLs. Only an extremely
small minority of ads originate from the same server as the page you are
looking at. The reason for this is that advertisers pay people to put
their ads on their websites, and these ads need to change frequently to
be effective. Hence these websites link to the advertiser's servers to
display the ads. Thus it's enough to blacklist the URLs pointing to the
ad-producing directories in the advertisers' servers.

  The advertisers can't change the URLs because it would break the millions
of websites which show those ads. Hence blacklisting is quite effective.

  Of course *new* ad servers and directories inside those servers pop up
all the time, but that's why the blacklists are updated.

-- 
                                                          - Warp

Post a reply to this message

On 12/07/2011 09:25 AM, Warp wrote:

>    The vast majority of ads come from external URLs. Only an extremely
> small minority of ads originate from the same server as the page you are
> looking at. The reason for this is that advertisers pay people to put
> their ads on their websites, and these ads need to change frequently to
> be effective. Hence these websites link to the advertiser's servers to
> display the ads. Thus it's enough to blacklist the URLs pointing to the
> ad-producing directories in the advertisers' servers.
>
>    The advertisers can't change the URLs because it would break the millions
> of websites which show those ads. Hence blacklisting is quite effective.
>
>    Of course *new* ad servers and directories inside those servers pop up
> all the time, but that's why the blacklists are updated.

So, in essence, your argument is that the majority of ads come from a 
small number of static servers?

Certainly I could easily believe that most of the more unknown 
ad-encrusted sites are just being paid to link to somebody else's 
adverts. But if I went to somewhere like a big movie studio, I would 
imagine all the ads on their site probably come from the same server as 
the actual content. (Then again, if you go to a website which exists 
solely to advertise a company's product... the adverts *are* the 
content, in a sense.)

Post a reply to this message

Invisible <voi### [at] devnull> wrote:
> Certainly I could easily believe that most of the more unknown 
> ad-encrusted sites are just being paid to link to somebody else's 
> adverts. But if I went to somewhere like a big movie studio, I would 
> imagine all the ads on their site probably come from the same server as 
> the actual content. (Then again, if you go to a website which exists 
> solely to advertise a company's product... the adverts *are* the 
> content, in a sense.)

  That doesn't really matter for two reasons:

1) Even in that case the ads usually come from a specific directory hierachy
which can be blacklisted.

2) If *one* website bypasses AdBlock, who cares? The fact that AdBlock works
on the million other websites who have external advertisers is reason enough
to use it.

-- 
                                                          - Warp

Post a reply to this message