Clear and transparent legal procedures of arrest and access to legal counsel are the best defense we have against this sort of mistake. This is why constitutional democracy is designed with these protections. And even with these defenses mistakes are sometimes made. The secrecy and unaccountability were undoubtedly going to end up with many of these mistakes.
The Us administration and its supporters are basically saying that it is okay to catch as many people as they can, including innocents, provided that they get some guilty terrorists in the lot.
These people are the terrorists. Arresting, torturing and making people disappear just because of their family name? Seriously, how different is that from blowing up people just for being in the wrong street at the wrong time?
They're right, this is an unprecedented danger - but it is them. In the long run, we're all dead. John Maynard Keynes