Not really. Warrants are not difficult to get. "We want to watch this guy because he talked to a guy who talked to a guy who blew up a bus in tel aviv." "We want to watch this guy because he petitioned his cable company to carry Al Jazeera." "We want to watch this guy because his cousin is Osama Bin Laden." What we've got now is "we want to watch the following 700,000 people because." If you start from what you know and work your way in, you get very different results if you start with a statistical analysis and work your way out. Not everyone named Moammar who lives in Detroit and speaks ill of the Invasion of Iraq is worthy of monitoring, which is why they get added to a list.Anyway, as far as alternative solutions go, "lead-driven" investigation is a bit of an oversimplification, don't you think?