CAPTCHAs (completely automated public Turing tests to tell computers and humans apart) are common these days. In case you aren’t familiar with the terminology, they are those images with obscured letters that you need to transcribe into a text box whenever you sign up for a new Web mail or forum account, for example. They may be annoying, and sometimes a bit difficult to puzzle through, but they have likely saved the world from a lot of spam.
When they were introduced, their goal was to make it impossible for automated processes to create email or forum accounts, making it difficult for spammers to use these free Web mail accounts to post or send spam. However, that was almost ten years ago, and the times seem to be changing.
This year, the CAPTCHA algorithms of three major Web mail services were cracked (see references below). Also, many of the CAPTCHAs associated with open source Web forums have been broken for some time. With unfettered access to generic Web mail services, it is likely that spammers will be able to increase their spam output, and that likely means more spam for you to sort through or your spam filter to wade through.