and vice president's younger brother got a package with a powdery substance saturday. francis biden is fine, and the fbi calls the powder harmless. now back to "to catch a predator." welcome back to our investigation into online sex predators. this time we are in rural harris county, georgia. so far we've seen a series of men trying to meet underage teens in internet chat rooms. well, now these suspects are under arrest and heading into a police interrogation room. again, some of what you're about to hear and see is explicit. here's chris hansen. >> it was stupid. i'm a stupid man. >> after "dateline" confronts a potential sex offender here in rural fortson, georgia -- >> you're free to leave. >> what's going to happen? >> get on the ground! get down on the ground! >> law enforcement working with the online watchdog group perverted-justice steps in. >> please don't put me -- >> put your hands behind your back. >> even the u.s. marshals and