The ad was part of a campaign for a police anti-terrorist hotline. It described a man who "likes to keep himself to himself", doesn't have a bank card and keeps his curtains closed, before advising that "this may mean nothing, but together it could all add up to you having suspicions".
You'd better not be a loner who doesn't like his neighbours peeking through the windows. If, in addition, you usually rely on cash rather than credit card, you're a potential terrorist.
This is the United Kingdom. This is 2010. For fucks sake.