Taking things through corpse looting and using thieving skill is one thing...people abusing access granted to a house to clean someone out is quiet another. Lowest of the low.
Sorry that happened to you Noc. It has only happened to me once, when an account was sold with a char friended to my house, but at least I had the consolation that it wasn't an actual breach by someone I trusted. I hope the same turns out for you.
-Skylark