Had an experience with a shoaler last week ... AFTER I had passed him when he entered into traffic (an unsafe entrance at that), at the next stop light he shoaled me. Then when the light turns green the a$$hat is in his big gear, so he's mashing and unable to get up to speed, slowing me down and eventually slowing another commuter down. I don't mind being passed, and I'm not the quickest when I'm commuting, but dammit, do NOT shoal me. I'd never do that.