Assuming that design could be detected, surely there would be a problem with this - since, using ID logic, everything is designed (either by God or by man) it wouldn't be possible to tell anything apart from anything else. Everything would test positive for design,
and we would be back where we started.
In this way, theory of ID would only be of utility if some life wasn't designed, and if there wasn't a superpowerful intelligent designer.
Whoops for all those Christian IDers!
Sorry if someone has already made this point.