It's all outlined in the Conditions of Carriage.

I've searched the topic thoroughly on FT and you won't get a better answer than they most likely wont go after you as long as you dont make a habit of it. There is no clear definition of habit, but I would imagine if you did it on a weekly basis they might frown on it.

Since AA doesn't handle airport security, it doesn't seem very likely they would tell the TSA to give you extra scrutiny.