In my day you only had to see the set working to caution the person of possible prosecution. At first we weren't given a choice, if the person visited didn't have a licence and the set was capable of receiving they were as good as nicked. After I threatened to resign over the stress it caused me the rules were relaxed to allow for discretion and believe me there were some people we visited that really needed help and not prosecution. Some though, usually full of bull sh*t and obviously well able to pay, were not given the opportunity to pop down the next day and pay. I tell you the sad cases really got to me and I later transferred to other duties.
Den