I guess, it depends where you live & where you use it.

For example:
Canada; you get caught (small fine)
. . . . United States: you get caught
(huge fine, some slammer time, and maybe you'll get your *** sued...)

Also, it might not be a good idea if you work at an office and use LimeWire.
(chances are they keep track of internet activity)

Use PeerGuardian. It helps to nagh gittin cauht.