Trespass by Landlord - The tenant has the right to peaceful enjoyment of the property, but this right can be modified by the lease. Unless the lease provides otherwise, the landlord does not have a right to enter the property without permission of the tenant except to demand payment of rent or to make emergency repairs. A tenant can sue a landlord for violating the tenant's rights.
Lockout by Landlord - Under most circumstances, a landlord should not "lockout" a tenant for any reason without a court order. The landlord may be held responsible for interfering with the tenant's right to "peaceful possession" until a legal court eviction. A landlord who illegally locks out a tenant risks being sued for damages.
http://www.dola.state.co.us/cdh/rese...s/tenant-l.htm