In some jurisdictions, copyright or the right to enforce it can be contractually assigned to a third party which did not have a role in producing the work. When this outsourced litigator appears to have no intention of taking any copyright infringement cases to trial, but rather only takes them just far enough through the legal system to identify and exact settlements from suspected infringers, critics commonly refer to the party as a "copyright troll." Such practices have had mixed results in the U.S.
Who can't be assigned a contract to enforce a copyright in some jurisdictions?