Just back from a few days in the UK. Almost everywhere that I went to eat added on an 'optional' 10% service charge. I've seen this before, usually for larger groups, but this time is was dinners for 2 or 3. And as for the charge being optional, you first off had to notice that there was a charge (most people don't, apparently), and secondly you had to ask for the charge to be removed. Most people, me included, wouldn't do that.
We asked one of the waitresses about it. She told us that most people didn't seem to check the bill or even notice. Occasionally some customers would be angry about it and take it out on her. She found it quite embarrassing. We were told that all the 'optional' additions were totted up and divided up amongst the staff, which they were paid monthly on top of their minimum wage. It was a way for the various places to pay more than just minimum wage.
So, is it a good idea to support low paid catering workers, or is it a further creep towards full Americanisation where tipping is obligatory and mobsters come for you for anything less than 15%?