IF YOU WANT to win a lawsuit from the RIAA, you're best off opening up your WiFi network to neighbors. It seems like this strategy might actually be working. Earlier this month the inability to prove who actually did the file sharing caused the RIAA to drop a case in Oklahoma and now it looks like the same defense has worked in a California case as well. In both cases, though, as soon as the RIAA realized the person was using this defense, they dropped the case, rather than lose it and set a precedent showing they really don't have the unequivocal evidence they claim they do.
Techdirt -- "RIAA Will Drop Cases If You Point Out That An IP Address Isn't A Person"