Katy Perry is on the hot plate for appearing in ads for Pepsi. It's not news that a celebrity is hawking the soda, but the harsh focus on sugary sodas is. The Center for Science in the Public Interest and other groups are running a full-page ad in Variety asking her to stop marketing Pepsi to young peeps. The hope is that celebrities will reconsider. Perry has a new LP coming out, so it's all in the timing.