These kinds of lawsuits have usually been launched by the owners of films that were box office failures (Far Cry cost $30 million to make, but grossed less than $1). Despite the fact that they have a legitimate legal claim, these lawsuits are seen by some as nothing but alternative revenue streams to small producing houses.
After theatrical release, you go to DVD, Netflix streaming, pay-per-view, network and cable syndication, airplanes, and apparently lawsuits against pirates:
As was widely expected, the producers of the big budget Hollywood movie, The Expendables have joined the coalition of the clueless with the producers of Hurt Locker in deciding to shakedown some of the movie's fans.
Once again, using law firm Dunlap, Grubb & Weaver under the name US Copyright Group (whose existing lawsuits of this nature haven't gone too well so far), a lawsuit lumping together 6,500 unnamed people accused of file sharing has been launched.
This is the first I've heard of a financially successful film going down this road, though. And I'm not sure I see the point. Most of these lawsuits have stumbled while trying to see thousands of people all at the same time in courts that don't have jurisdiction over them, causing unnecessary delays and mounting legal bills for the producers (and a regular revenue stream for the lawyers).
Seems like a giant waste of time.