In his "The Numbers Guy" column, Carl Bialik of the Wall Street Journal takes a critical look at a recent study showing that taxi passengers have lost tens of thousands of cellphones, PDAs and laptop computers over the past six months. "Too much precision in a statistic is a good signal to dig deeper into the methodology and the origin," writes Bialik. "In this case, both are dubious." Most damagingly, the survey was funded by Pointsec Mobile Technologies, which claims to protect data on mobile devices in the event they are lost or stolen. In addition, the study relied on extraordinarily small, non-random samples of taxi drivers.