I've been interrogated by police for even less reason than those kids. One time I was driving down in Washington (I live just over the border in Canada), it was 3am on a Tuesday. I was going pretty much exactly the speed limit when a cop pulls me over. His reason was, I quote, "'cause you got a BC plate". He asks why I'm driving around at 3am, so I tell him that my buddy and I were just out driving for fun (we were 17 and bored). He says that he doesn't believe us and that because we're from BC, and its the middle of the night, that we must be smuggling drugs over the border. So he calls in backup and says he's gonna search my car. Ok, nothing I can do, I consent (he seemed surprised that I did). He and his backup spend about 20 minutes tearing apart my car, pulling out everything from my trunk, including the liner and spare. Oh, did I mention it was snowing pretty heavily and I was wearing shorts and a t-shirt. Of course they find nothing and we have to put everything back in the car. Then the cop tells us that he still thinks we're drug smugglers and that he'll be watching us. He then follows us out of town for about 15 minutes before turning back.
I have had the worst experiences with American cops, I think they just don't like foreigners. Actually, American border guards are even worse. I hope Canadian law enforcement treats our American neighbours better than that.