Decentralise Your Data - Or Lose It
Aside from the obvious one of not trusting the UK government with personal data, the other lesson to be learned from the catastrophic failure of "security" by the HMG is the obverse to one of free software's key strengths, decentralisation. When you do centralise, you make it easy for some twerp - or criminal - to download all your information onto a couple of discs and then lose them. A decentralised approach is not without its problems, but at least it puts a few barriers in the way of fools and knaves.