Gig or playback?

Recently, a lot of groups and artist use electronic devises to play their songs. This, including pre-recorded sounds, voices, instruments, and so on… When they playing live, they are really playing live?? Or we can consider this is only a playback. Make sense go to see play “live” to this artists?? 

In Las Vegas there are some rules for the DJ’s in a manner that they could use their electronic devises but the pre-recorded sounds can be complete, in a way they should mix music live… This rule should apply to all the gigs of electronic music??