Well, Here is how a booter works. When you specify a Yahoo! Username into the program and click lock it will attempt to sign-into that account using random numbers for the password. After about 10 attempts or Less Yahoo! Locks the account for security reasons. Now, This is so easy to make but alot of people dont know how easy it is. Now you may ask if my account is locked how do I by-Pass it? Well you by-pass it by signing in on a foriegn country site. So if your account is a registered account on the Yahoo! American site (Http://www.Yahoo.com) go to The U.K. Site and log-in (Http://Uk.Yahoo.Com) and you will be able to bypass the 12 hour lock on your account.
I consider Yahoo! Account lockers lame but fun. Let's say some lamer is harassing you then when that person signs off lock his account and he can't sign on for twleve hours on messenger, but he can with email using the trick above. Still takes care of a lamer for 12 Hours. If you dont know how to program these kinds of programs look at sources on my site or booter sites or go to Planet-Source Code (Http://www.Pscode.com) and look for Yahoo! Modules and Api Calls. If your a good Visual basic Programmer like me you can easily make your own booter with the winsock and api calls.