these kind of lawsuits smell of commercial blackmail...everyone knows the fitbit is not a lab or EKG quality HRM, but it's a general fitness tool. I'm not a fitbit user (Polar & Garmin, with chest straps), but if people like them and it helps them stay fitter, then more power to them. From what I read in the lawsuit, there's nothing even claimed in it that makes them "dangerous"- the plaintiffs are privileged against libel and slander when they say things in legal pleadings, so they can try to get a large settlement from the company to avoid this type of publicity. I'm glad the company didn't cave in.
a friend's daughter, who's been a total couch potato, got one for Christmas and now is fanatic about getting her "steps" in, goes out walking and jogging, etc. and trying to get her heartrate up while she does it. Good gateway to kettlebells, eventually! haha