Just over a year ago, we started seeing a huge deluge of anonymous posters making spam posts on the thinkbroadband forums, beyond a level which we could manually work around in a sensible way. We started looking at patterns of spam and fairly effectively prevented it using those patterns in a fairly simple detection algorithm looking as typical human versus computer behaviour. Even users on our forums spotted that spam often had the first ‘icon’ you could select to represent your post used even though it wasn’t the default one.
We tweaked the settings as the spam bots changed their style but for at least a couple of months we had quite a few get through which was annoying. When BBC News ran an article on reCAPTCHA I thought this would be ideal both to stop our spam problem and help decode old books. It provides an easy-to-use CAPTCHA solution which also has tools to help blind people get around them using audio tools.
This spam fighting tool also helps decipher old books since it shows two words, one of which it recognises. It doesn’t know what the other word says, so by solving the two words you prove that you’re human, and help digitise books by deciphering the other word.
It does present some words which are a little bit too difficult to read.. The one above isn’t too bad, but illustrates the potential problem. You can refresh it to another word pair of course.
My blog doesn’t receive that much spam but since my inbox is full enough as it is, cutting out every last one would be idea, so it’s now implemented on my blog too for comments, thanks to the plug-in for WordPress.