Interesting Fact - The Law

In the UK you can be arrested for using someone's wi-fi network without permission.

(The Communications Act 2003 says a "person who (a) dishonestly obtains an electronic communications service, and (b) does so with intent to avoid payment of a charge applicable to the provision of that service, is guilty of an offence". This practice is known as piggybacking or mooching. Mind you if you can even find a wifi signal in the UK you're doing ok.)