Stay focused on the problem you want to change. Do confront them in an assertive manner. Do address inappropriate behavior by staying focused on the problem and the desired solution. Do listen to their side of the problem before you talk. Repeat back what you heard your teen say and try understand where they are coming from.
Parents always have veto power over teens.
Just don't abuse the power. This is the best secret of all. It's hard enough growing up and discovering who you are without having some fun every once in a while. The challenge is finding a balance between fun and responsibilities. Make some verbal agreements about whom, when, where, and what is considered appropriate fun.