Boyfriends, Friendships, Facebook and Threats. - WARNING - LONG POST -

First of all some background info :
I found out some1 i knew was gay, to be called X during this post, we eventually started going out, it went well for a while though after a while i broke up with him as i just didnt really feel a connection anymore.

Now the issue:
X has had lots of issues with his dad beating him at home, and he talked to one of my friends (Now to be called Y) about it, trying to vent some frustration i guess, Y then blocked him on msn because Y felt he was getting annoying by not moving on from the subject. X then got VERY mad and started saying he would spread lots of things about Y (some true, some not, but still very personal and unfair to spread) around school and on facebook as well as insulting her generally. After a while they reached a kind of civil relationship where they managed to not be angry at each other (though i was still mad at X).

Later on however Y felt that that X should not be forgiven (also because he was being very angry about the subject and refused to talk about it sensibly). Me and another friend were sticking up for Y this whole time as we felt that yes, he may have some major issues at home (which we DID report to relevant authorities), it's no excuse to take it out on Y (he said that he was unstable due to what was going on at home).

The most serious part, after me, Y, and my other friend agreed he shouldnt be forgiven, (mostly because of how he was being so agressive about how to deal with it and he wouldnt talk about it without swearign and getting angry, not just because of what he was saying and threatening to spread) he simply got more and more agressive, and allthough i cannot make exact references, he did suggest some extremley dangerous things that would effect me and my family, as well as Y and hers. He also made a refernece to something that would be very dangerous.

Now we basically hate him, and im not really even sure why i wrote this, theres not much you can do. Should we tell someone about all this and him being threatening, but my worry of that is that the authorities could find out about me and X's previous relationiship which i would really rather they didnt. Should we just forget about it all and try to move on :/

Any comments, thoughts, suggestions or questions would be appreciated.
P.S - sorry its so long.