"After all, we don't want to be guilty of racial profiling. "
First of all, I don't have a major problem with racial profiling when persuing criminals or terrorists
That said, it's pretty stupid to think that the bad guys would not attempt to use people who do NOT fit the profiles, so you don't gain anything.
In the case this thread is about, these people WERE singled out by racial profiling, were identified as Americans Citizens and were not given ANY information of what their rights were or what they were suspected of or why they were being held. THIS IS WRONG for anyone.
Once the Border patrol KNEW who they were and they were NOT on any list of criminals, there was NO reason to hold them.
Per your first comment, these people WERE rounded up, and WERE held for no reason.
...and after being investigated, they were released.