The issue at hand here is how do we prevent terrorist attacks from within our own borders without mass surveillance of the population and without the profiling

The issue at hand here is how do we prevent terrorist attacks from within our own borders without mass surveillance of the population and without the profiling of certain populations (ie middle easterners, northern africans, etc)?? I don't think we need mass surveillance since it creates more useless data and not enough indicators someone is planning something. So where is the line drawn between mass surveillance and no surveillance? How do we keep this country safe, without infringing people's freedom?