Yeah, same thing happened to me. Was just casually going through security, TSA stopped me, directed me to a holding cell, and kept me isolated for 5 hrs. After that, they interrogated me as to why I would fund multiple Citi bank accounts using a credit card, stating that my activities were "suspicious" and accusing me of being "an enemy of the state". They offered me asylum if I agreed to refund Citi over 300k miles in punitive damages, which I agreed to. (Either that or I would be serving as some dude's butter cup in prison for 10 years). Moral of the story, don't screw with Citi lol.

This deal is clearly YMMV and might not work for some. Unfortunately, it appears I'm on the other side of the fence now. One thing is for sure, someone mentioned prepaying your credit card to get around the CL, that is NOT a good idea, they might cancel your card for that. You can however pay AFTER the purchase have posted but before your statement closes.