People talk about "give an inch and they'll take a mile" and "the slippery slope", or "letting the camels nose into the tent", and we all know what those phrases allude to. The sad part is, they seem to be particularly applicable to government. I was born and raised in the UK, which sadly over the last 20 years or so has really become much like the rest of Europe, with very much of a "Nanny State" mentality. In the USA, we seem to be rather too willing to head in that direction too.
The problem seems to me that once a government department or agency has some control over a particular area, they inevitably want more control. Whether this is as attempt to further justify their existence and the need to continue their control, or if it's from a sense of "You know, if we can help a little by doing ABC, then we could really make an impact by doing XYZ...", I don't know - and in some sense it really doesn't matter.
The founders of this country were apparently well aware of this tendency, human nature being what it is, and made numerous provisions in the Constitution to avoid it happening in the new, better country they were trying to build. It's surprising that we seem to have forgotten it - or maybe it's not so surprising at all.
The latest movement down one particular slippery slope is the lengthening of the time the National Counterterrorism Center can retain records of Americans from 180 days to 5 years. According to the NY Times article below, that's for a person where there is no suspicion that there is any connection to terrorism. Huh? Apparently, it may be to give more time for data mining the information.