Nine men who were convicted of sex crimes, served their prison sentences and are now indefinitely confined to an Iowa mental health unit have filed a federal lawsuit against the state, claiming its civil commitment program is unconstitutional.

They say the program fails to offer adequate counseling and other services that would rehabilitate them enough for release.

The lawsuit, filed in September 2012 in federal court in Cedar Rapids, highlights the difficult balance between keeping dangerous sexual predators off the streets and not violating their constitutional rights.

More than 5,000 people are believed to be held in sexually violent predator programs in 20 states and the federal Bureau of Prisons.

Judges in Minnesota and Missouri found programs similar to Iowa's unconstitutional in the past year and ordered changes.