Is this legal (marketing)?

If I make a painting of another person without their consent, based on a photograph the person has published online, am I violating the law, if I sell the painting afterwards, or print it on consumer products like cups/puzzles/bags in mass production?

Hmmmm sounds like it could upset someone, but I suppose they would have to prove the painting is based on them and unless you have made it really obvious it is, I suspect this will be hard for them to do so.

Might be best just to ask someone - they could well just say yes!