sapOp-Ed: Last week I wrote about energy harvesting; here is a new example. MIT researchers are studying ways to power anything from subway trains to rock concerts by capturing the power of simple movements -- in these two cases it's the movement of human feet -- and to borrow from Dave Barry, isn't "The Electric Stampede" a good name for a band?  The more I think about this concept, the more I like it (energy harvesting, not the band name.) But what's the other side of the story? Can you think of any logical arguments against energy harvesting? Share your thoughts using the comments form below. (In other MIT news this week: the school's seventh-generation solar home is almost ready for its debut.)