Citing several unnamed sources, TechCrunch reported yesterday that merger talks between Microsoft and Yahoo were back on. Investors responded, buying Yahoo stock up 10.5 percent from the day's low to $23.71. Now CNBC says the rumors were false. Reporters' reporter Kara Swisher of BoomTown — who did a bit of reporting on the rumor and happily quashed it in a report today — admonished TechCrunch, writing that "anyone reporting on the situation should have been deeply cautious about floating rumors." But we wonder: Cautious for the sake of whom? Investors buying up stock based on a report citing anonymous sources, written by a blogger known to write about companies he invests in? Ms. Swisher, we're pretty sure those folks can't be helped. They're called "market inefficiencies" and they are who real investors exploit on their way to wealth.