Lag switches are silly and don't even really provide any kind of advantage. Most likely the player is dead when his connection finally catches up, as evidenced earlier in this thread with that x-lis or whatever guy who got his face exploded.
Speedhacks: carnage marauders with speed bonus with predation and picking up the speed boost
GCD hacks: carnage marauder using berserk and retaliate
In other words, l2p
unless you are a stealth class
lag switches can be usefull if you are stealthed out and go and cap a door... seen it done
a guildie actually knew this persons dad, and confirmed that he was in fact using a lag switch. this was in june or something though. Havent seen it recently