I been in and out of the country three times in the last ten years with no documentation, not for any nefarious reason, but more just because I am a bit lazy and couldn't be bothered with sorting out the paperwork.

So is equally useful for us smart emigrants creeping out of the UK as well. Personally, I could care less about immigration. I don't view it as a major risk and think that trying to link travel to terrorism is ridiculous. The people most likely to have the means, motive and opportunity to commit a terrorist act in a particular country are the people who have lived there all their lives.