When the bots attack! [closed]

Question

What are some popular spam prevention methods besides CAPTCHA?

Answer 1

A very simple method which puts no load on the user is just to disable the submit button for a second after the page has been loaded. I used it on a public forum which had continuous spam posts, and it stopped them since.

Answer 2

Animated captchas' - scrolling text - still easy to recognize by humans but if you make sure that none of the frames offer something complete to recognize.

multiple choice question - All it takes is a ______ and a smile. idea here is that the user will have to choose/understand.

session variable - checking that a variable you put into a session is part of the request. will foil the dumb bots that simply generate requests but probably not the bots that are modeled like a browser.

math question - 2 + 5 = - this again is to ask a question that is easy to solve but prevents the bots ability to generate a response.

image grid - you create grid of images - select 1 or 2 of a particular type such as 3x3 grid picture of animals and you have to pick out all the birds on the grid.

Hope this gives you some ideas for your new solution.

Answer 3

Please remember to make your solution accessible to those not using conventional browsers. The iPhone crowd are not to be ignored, and those with vision and cognitive problems should not be excluded either.

Answer 4

For human moderators it surely helps to be able to easily find and delete all posts from some IP, or all posts from some user if the bot is smart enough to use a registered account. Likewise the option to easily block IP addresses or accounts for some time, without further administration, will lessen the administrative burden for human moderators.

Using cookies to make bots and human spammers believe that their post is actually visible (while only they themselves see it) prevents them (or trolls) from changing techniques. Let the spammers and trolls see the other spam and troll messages.

Answer 5

Ned Batchelder wrote up a technique that combines hashes with honeypots for some wickedly effective bot-prevention. No captchas, just code.

It's up at Stopping spambots with hashes and honeypots:

Rather than stopping bots by having people identify themselves, we can stop the bots by making it difficult for them to make a successful post, or by having them inadvertently identify themselves as bots. This removes the burden from people, and leaves the comment form free of visible anti-spam measures.

This technique is how I prevent spambots on this site. It works. The method described here doesn't look at the content at all. It can be augmented with content-based prevention such as Akismet, but I find it works very well all by itself.

Answer 6

A friend has the simplest anti-spam method, and it works.

He has a custom text box which says "please type in the number 4".

His blog is rather popular, but still not popular enough for bots to figure it out (yet).