Excellent

This plugin is remarkable even though I have no idea exactly how it works its magic.
The captcha I was previously using had the “solve a math problem” approach, but recently some bot figured out how to solve the math, or least frequently enough to be a pain, and I began getting a horde of spam user registrations and a lesser amount, but still annoying number, of comment spam.
I switched over to Goodbye and the excellent reporting showed that it blocked 164 spam registration attempts in the first 24 hours. Not one made it through.
Highly recommended!

Update: 11/27, after one week of installed use: 954 spam attempts to register as Subscriber blocked – not a single one got through. GoodBye indeed!!