One of my clients has started noticing a pretty large number of bogus 'memberships' being created in their database through their web page. Membership itself is free, and run through a PHP page that uses CWP to submit the information to the database.
The bogus records are probably coming from web-bots and give results like: first name=wqmuyjoz, last name=wqmuyjoz, email@example.com, city=New York, country=Cook Islands. Ideally, I'd like to block the submission of this bogus data before it ever gets into the database, since that just makes work for a human to go through and delete the records and whatever progeny they create.
What methods have you used to combat this unwanted activity on your sites?