The Chicago Sun-Times recently reported on new eviction measures put in place by the Cook County Sheriff's Office. These new measures are designed to alert tenants that their rental unit has been foreclosed upon by their landlord's bank or mortgagee. Many tenants do not become aware that their landlord is in foreclosure until the Sheriff comes to actually remove them from the premises.
http://www.suntimes.com/news/metro/1139296,CST-NWS-evict02.article