Your landlord's placement of a lock on your trailer to prevent you from moving without paying your rent in full is a violation of many state's statutes precluding the landlord from using self help to collect due rent from the tenant.I suggest that you first speak with your landlord in person about what he or she did and follow up with a written letter to try to get the lock voluntarily removed. Keep a copy of the letter for future use.If the landlord refuses to voluntarily remove the lock, your recourse would be to contact a landlord tenant attorney about the situation.