Was I Giving Up My Rights By Allowing TSA Scan or Pat Down?

The Transportation Security Administration has come under criticism for the level of detail in the full body scan or enhanced pat down procedures of a 6 year old girl or a 95 year old woman with adult diaper. I believe I was not giving up my constitutional freedoms by not opting for the pat down or not cooperating with the TSA. Others say that our rights are slowly being compromised and soon there will be checkpoints to get from one state to the next. What does the law specify and why don't more people complain?