When I was doing free hosting I found that there was alot of abusers.
I finally had it taken down, after I provided proof of domain ownership. Visit DigitalPoint Forums.
If your also with ParadoxServers... then keep a look out if you have a BIG forum or website. Your data may get stolen and used without you knowing.
I send host ninja assassins....
No there's not much you can do but delete there account when you find out. No point blocking there IP as they will only come back with a proxy.