SPAM and THANKYOUS.

[bigsofty]

Banning the ip range can take care for most dynamic ip's from a certain ISP, look up Whois for the spammers ISP range... This can get time consuming though.

Requiring an introduction post before posting is allowed, can add further complications to bots too.

Excuse me if I'm showing you to how to suck eggs here BTW.

Talking of which, I think you'd be surprised at the percentage of bots compared to humans Ian, there good at appearing human, once there in the system.


Cheers,


Ian

[Kitty Hello]

I have such questions in. Like:
"3 plûs 5 = "

I used special umlaut characters, that are human readable.

[Ian Price]

Talking of which, I think you'd be surprised at the percentage of bots compared to humans Ian, there good at appearing human, once there in the system.

I know the ratio of bots to humans is very high, but it's usually possible to tell the difference. And it depends on what they are pushing too. There will always be trolls and destructive funsters. You can't get rid of them completely, but you can make it harder for them to bother us.

[Slydog]

Re:

Requiring an introduction post before posting is allowed, can add further complications to bots too.

Or could all first time posts be flagged for review / verification prior to being cleared for the forums?
Down side is that new users may miss out in a discussion in a timely manner.

Instead of a math CAPTCHA you could ask 'Type every RED character' and randomly choose a color each time so it's not RED every time, and have random character with random colors in the CAPTCHA image.  If that's easier.

Are spammers cracking the CAPTCHA image to OCR the characters inside?
One method I was thinking about to prevent (or reduce) OCRing CAPTCHA data is that instead of solid (or gradient) colors (for the background AND letters) you use more of a 'noise' effect.  Each pixel is randomly calculated to be in a range of values (grey scale).  Background and characters can have the same range but have the background weighted to use the dark end and the characters weighted to use the brighter end of the scale.

It will look like random pixels of various shades, but where the characters are you'll notice it tend to be brighter on average than the background, but each individual pixel doesn't give away it's true identity (background or character).  Can't really predict how effective this would be but my hunch says humans should be able to tell the difference easily, and good luck writing code to OCR the image!

[Edit]
Well, maybe my idea isn't that great.
I tried it in a paint program and the ranges have to be quite different to see the characters, but more experimenting would be needed!  Still, try OCRing this image!  You'd have to have logic to track clumping of data, as a white pixel could still mean either background or character.


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[Marmor]

a email controlled forumaccount would help ..

[Kitty Hello]

That's the last resort.

[Ian Price]

The trouble with the RED and non-OCR characters is that people with visual impairments can't read/see them clearly. You shouldn't exclude real people just because they can't read the CAPTCHA.

[MrTAToad]

You usually have an audio representation with noise added

[Ian Price]

You usually have an audio representation with noise added

I was speaking specifically about the two examples above, and using captcha as a generic term.

[MrTAToad]

Ah right

[Wampus]

I thought, "What about moderator approval of new accounts" but that wouldn't stop anti-spam taking up time because mods would still need to trawl through the account requests. Might take less time to do that though?

[Kitty Hello]

As said, Admin approval will be a last resort.