I don't have a problem with it really. The Knife's current live show has attracted a lot of discussion due to the fact that much of the music isn't being played live, at some points there are mimed vocals and at times you can't tell who is playing anything and it is more of a dance performance. After reading about it I was a bit wary before seeing them at primavera sound but in the end it was probably my highlight of the festival. I absolutely loved it, had a cracking time. As for the question about DJs, that's an entirely separate issue. What do you mean is there such a thing as a live dj? All of them? If they weren't djing live that'd surely jsut be sticking on a playlist. Anyway imo a techno dj, mixing different part from different tracks to make a new whole, is doing as much live as other musicians.