This requires a little more of an explanation but, in general, a landlord cannot change the locks or turn off utilities while the tenant has a right to be in possession of the premises. This is what eviction is used for. A landlord who resorts to self-help remedies may face problems in landlord-tenant court for an unlawful or constructive eviction (not actually evicting the tenant but doing things that are almost the equivalent of forcing the tenant out like shutting off heat in the winter or turning off the electricity.) I can only wonder what the situation is but typically this occurs when the tenant hasn't paid rent for months and the landlord has decided to take his or her chances. Sometimes it's difficult to blame them since the eviction costs are usually never recovered and the security deposit doesn't cover it.