Re: Fighting Splogs
Signup questions and codes are a good supplement to the other methods but are also ultimately fallible. In the same way that Captcha is rendered ineffective by human relay attack, so to are questions; it will just take time for spammers to catch on.
It seems to me that the way forward is to incrementally roll out new defences, only presenting new defences when the old ones have been broken. As soon as lots of sites use a defence, that defence will probably soon be doomed to failure: spammers will only take the time to develop new exploits when a particular method of defence becomes popular. I believe this is the only reason why the hidden fields method currently works: its not sufficiently popular to bother coding an exploit for it (even though such a task would take about five minutes).
