Looking at the posts number gap, I take it no_ball
Post# of 32638
Libelous posts, lying, impersonation, impeding/sabotaging a company from doing business, etc.
If that was my employee, I call them into the office and say...
"One of us is going to have a very, very bad day and I'll give you super top secret insider information...It's not me.
If you're lucky, sometimes the Lord give you get a chance to set it right, but most of the time, this type of behavior goes unpunished. This ain't one of them times. We cannot have you working for us."
I'd take his computer and kick him out of the building. I'd lock the door too as I'm sure he'd try to come back every 10 minutes with new disguise. .
Good luck getting a new job, other than iHub, with no job references. You could imagine how he'd troll his former employer for decades afterwards.