Long story but will keep it short.
I was like 18, My friends and I had gone to a Stones concert and some bikers had asked for smokes, my friend gave them some and in return they gave him some weed, he didn't want it so another buddy (who doesn't even smoke) kept it in his wallet.
A year later 3 of us go to the NY city and cross the border from Montreal. I was driving, and the customs agent pulls us over. To no surprise they check our wallets and one of the guys discovers this crap, it was so little, like a tenth of a gram and so stale that at first he didn't know what it was.
Next thing I know, is they take him away and hand-cough one of his arms to the cement floor the kid was 18 at the time, real uncomfortable. They were being such arrogent bastards you could not imagine. There was one guy with a gun to my buddy's head!!. They deliberately made us face my buddy as we were being interrogated like terrorists and then I hear the guy say to my buddy (that doesn't even smoke cigarettes!) "Son don't move, cause I'll be forced to shoot you". Those jerks counted our money to the last penny, it was like $2.540 and told us that we would have to pay to take the car back since it is going to get impounded. It was the exact same amount that we were all holding, they didn't even leave us with gas money. Then they tell us that they need another $250 or else my buddy was going to jail. Those jerks knew they had taken all our cash and wouldn't accept visa, come to think of it, they were probably playing with our heads like greedy whores to see if we had more $$ . We were then strip-searched, thank god I didn't get the glove treatment.

. I'm not a drug user but since then, I'm parranoid as hell when I cross that border.