I believe that would constitute illegal harrassment. As previously posted, landlords cannot control the actions of tenants. Would you want your landlord to control your actions concerning your children and how you speak in public?
Your beef is with the neighbor and you can use video tape...
odd advice
If someone who is
1) a known acquantence and
2) has the key to the apartment and
3) removes personal belongings which are not in your possession and
4) you do not assist them,
then in what state is that considered giving someone else's property away.
I think the outcome...