Most likely, just entered a random email and a offensive password and came up with.... Funny that, they actually think they've got my mail & password now... noobs! I can see some people falling for it though. edit: they also say in the terms...
yeah i fell for this (tired and possibly drunk... ) - it does actually give a service if you use it with valid login details, though. there's plenty of legit tools you can use for this on mess.be. it steals your password, logs on for you and send messages to everyone on your list with that link. AVOID, and i'd recommend mods remove that link, or more clearly label it as a definite no-no.
People have been falling for the 'who blocked you' type scams for ages. There is not way to know, do not go for them. Incidently I used this to steal a friends password, so they can be useful.
I find it really ridiculous when people fall for these things, they're always so blatant. Especially the myspace ones, why would you have to log into myspace again after clicking a link, you are already logged in!!!! Having said that, according to Tom, I had it done, although I reckon is was because I posted about 30 bulletins in a few minutes.