XKCD has SETI’s number

For the record, I think SETI is a good idea, and that most people misunderstand Drake's equation (it's a way of estimating the number of civilizations in the galaxy, not a way of determining their number), but still, this XKCD cartoon is funny (click to see the punch line):

Hold the mouse over the picture on the XKCD page to see what he really thinks. I disagree with him on that, too. We've only just started looking. :-)