I just witnessed something that I found interesting. A homeless man in my neighborhood was in front of me at Starbucks and he asked for a large cup of hot water with a lid. They give hot water for free which is quite useful in the cold streets of SF. You could make cup o noodle soup, for example.
But the other thing is that you can then use the cup and sit in another Starbucks to ask for a free refill of coffee. I've seen this happen before and assumed that people pulled cups out of the garbage, but maybe they had clean cups already.
Anyways. It is nice that Starbucks gives this guy hot water and a cup and treats him nicely. And now you know how you can get free coffee at Starbucks!