often they'll loan out pieces of art to museums, so they get the tax benefit and they get to keep the art pieces. I'm not sure how many of them are giving cash away to non-profits they don't have some controlling interest in (seems it would be rare but maybe I'm wrong)
You're somewhat misremembering a real thing. It's possible to profit by donating a piece of art to a museum and claiming its value to be much greater than what you'd get on the open market. This is tax fraud, though, and the IRS will probably notice.
