Terror Suspects Buying Firearms, U.S. Report Finds

I'm really not in favor of taking away people's rights just because the government identifies them as a suspected terrorist, but I really do find it odd that we have no problem taking away a lot of basic rights in the name of fighting terrorism, but somehow, the right to buy a gun doesn't seem to be included in those. Why is it we can detain people indefinitely, ship them off to other countries, deny them due process, toture them, etc., but somehow, we have a problem keeping them from buying weapons. Oh well, at least they probably can't get on a plane.