Disgruntled staff members at a downstate juvenile detention facility have responded to limits on the use of solitary confinement by seeking criminal charges against detainees for trivial infractions, the American Civil Liberties Union of Illinois alleged Monday.In a motion filed in federal court in Chicago, the ACLU asked U.S. District Judge Matthew F. Kennelly to halt what it contends are malicious prosecutions pursued against juveniles living at the Illinois Youth Center in Harrisburg.Kennelly presides over litigation …