It's interesting that surveillance and data retention by the government is framed as a moral issue in these discussions. I happen to think that laziness is at least as big a factor, and it's what really drives behavior in many cases. It's all about the path of least resistance. In the old days of paper-based records, you had to go through several extra steps to keep a record, using a copier, for example (or carbon paper before that). Even the old computer systems had bulky, expensive tape drives which held fairly little data. Assuming you wanted to keep any given bit of information around once you'd grabbed it, you then had to file it, keep it dry, and so on. This meant that data retention cost money in terms of creation, storage and indexing (which they used to call "filing," and it took even more people), so you had to justify the expense of keeping a record of an event.
Fast forward a few decades: nowadays, if you run a network of any kind (even a small one at home), you have various servers, firewalls, daemons, and so forth running all the time, each writing the details of their activities to various logfiles which sit on disk and cost very little to index, search and store. In addition, since the records are created automatically, you have to actually *do something* to get rid of them. That means adding an extra "deletion step", whether it's writing a script or otherwise, which means at least some expertise is required, which means you have to pay someone, and, if you are in government or business, you have to justify to someone why you are spending money to have less information about your systems, users, what-have-you. This is especially problematic if someone can find you blameworthy for doing so. Which they will, especially if it is politically or financially advantageous to do so. And it always is.
All of this is obvious; I'm not saying anything new or interesting here.
