One of the greatest (currently) unaddressed issues in WordPress is that there's no way to moderate user registrations. There are only two settings: anyone can register themselves (the administrator will be notified) and only the administrator creates registrations. There's no in between and no hooks for changing this with a plugin. I leave registrations open so new readers can create an account whenever they want. The problem is that spam bots will also generate registrations. I get three or four spam bots trying to register each week.

If the user name or e-mail isn't obviously spammy, I'll send an e-mail asking for confirmation. If I don't get that confirmation (and I rarely do), then I know it's spam. Here are the e-mails from the latest instance.

The automatic notification:

New user registration on your blog A Feast of Crumbs:
Username: John Doe
E-mail: nondescriptmail@majorisp.com

 
My challenge:

Hi!

Are you a spam bot?

I get a lot of bogus registrations. If you do not respond to this message, I will assume yours is one of them and will delete your account.

 
The registrant's response to my challenge:

No I'm not a spam bot. Don't even know what that is. I just got this card from Philip Morris to sign for savings and coupouns for my smokes. I went to the web site it said to and this is where I ended up. So if I'm on the wrong site pllease let me know so I can get to where I need to be. I smoke Marlboros and have for 30 plus years. I just would like to get some coupons mailed to me.

Thanx John

 
Next from me:

Oh! Somehow you ended way offtrack, friend. You registered on my blog at feastofcrumbs.com. I think what you're looking for is http://www.smokersignup.com/ That's where you sign up for coupons for Philip Morris products.

 
Next from him:

Hey, Thanx alot friend. I appreciate the info.

Wow. Dude was really lost. I should have asked for his credit card number to confirm his age.