I suspected this might happen once I released RegisTrap to the public. I had four new spam user registrations on my site when I checked it today (having last checked it maybe two or three days ago). Previously I’d only see about one a week with RegisTrap running.
It was bound to happen. The rules RegisTrap employs are fairly simple, and the “bots” are constantly being modified. I have no idea how many registrations RegisTrap has blocked in the time it’s been running — perhaps my next step in developing it is to add a logging feature. If there were only four (or even maybe a dozen or so) spam attempts on my site during this time period, then RegisTrap seems pretty ineffectual. But if it actually blocked a ton (metaphorically speaking) of spam registrations, then four sneaking through doesn’t seem so bad.
If anyone out there is using RegisTrap and cares to comment on ways I could improve it, let me know! Meanwhile, as time allows I am going to pursue the logging functionality, if only for my own edification. As valuable as the logging feature would be, it goes against the spirit of simplicity inherent in the plugin. I really don’t want to write anything to the database or filesystem.