While it seems that scammers for the most part get away with whatever vile tactic they have drummed up, we do sometimes hear stories of them being caught and punished. Some people aren't content with sitting and waiting for the law to act, and instead choose to take things into their own hands. A particular group of vigilantes led by a “Shiver Metimbers” is actively working to lure scammers and defeat them at their own game:

So-called 419 scams, named after the section of Nigeria's criminal code that covers the conduct, are the most common type of con; victims are sometimes left penniless.But Metimbers and crew turn the tables on scammers one by one, boomeranging the tricksters' own tactics to entice them into performing outlandish tasks in desperate pursuit of cash -- then trumpeting evidence of the con artists' naïveté for the online world's amusement.
The group will work to make a scammer believe they have found a potential target, and attempt to convince the scammer to perform ridiculous stunts or even send them money. Of course, this doesn't get the scammer off the Internet, but perhaps could teach them a lesson via this so called “Scambaiting”.

Groups like this aren't exactly new. Similar tactics have been employed for quite a while now, and the 419 groups are often the largest and easiest anti-scamming targets. Getting involved in this could easily be dangerous and isn't something the casual net user should participate in, but is fascinating nevertheless and the article is a great read if you like to hear stories of vigilante justice.