Recently, for Strava, the inevitable happened. It was announced they are being sued.
In this case Kim Flint, who was 41, rode his bike down treacherous South Park Road in the Berkeley Hills. That segment was later marked as "dangerous" by a user, but he still has the record descending nearby Centennial Drive. Kim obviously liked to put it on the edge downhill. There's risks with that, and in his case, he lost the bet.
The key issue here is what responsibility Strava has for Kim's risk-taking? If I promote a bike race on a course which is obviously dangerous, and people enter the race expecting some degree of safety, then if someone dies in the race I expect I'd be fairly exposed. But the historical standard for bike racing is at a relatively high level of risk. Anyone who's tried to stay with the lead group descending from Hamilton summit in the Mt Hamilton Road Race knows that.
But the question in this case is: is Strava acting as an event promoter in this case? Strava's position is likely that they are simply recording and quantifying data that is willingly provided, extracting times over user-defined segments. They use graphical medallions for riders who rank near the top for each segment, which suggests reward, but is it really a case of them encouraging riders to go fast? And if they are, is that a problem?
To answer this for myself (I'm not a lawyer so have to do the best I can) I refer to the California Vehicle Code. Strava has a multi-national customer base, but they're based in California, so this seems a reasonable choice.
Here's a link to section 23109 of that code. A key portion is as follows:
23109. (a) A person shall not engage in a motor vehicle speed contest on a highway. As used in this section, a motor vehicle speed contest includes a motor vehicle race against another vehicle, a clock, or other timing device. For purposes of this section, an event in which the time to cover a prescribed route of more than 20 miles is measured, but where the vehicle does not exceed the speed limits, is not a speed contest.
The key language here is "motor vehicle". When this term is used, it explicitly excludes human-powered transport. Bicycles are subject to "applicable" portions of the vehicle code (even though they're not defined as vehicles) but "motor vehicle" portions don't apply. Usually the code refers to "vehicles" without the motor part.
So what this says is under the law I can challenge my friends or whomever to an informal bike race whenever I want, as long as no other sections of the code are being violated. The code is full of provisions like "exercise due care" so reckless behavior is generally disallowed, but riding uphill is usually no problem, or on open flat roads.
So if I want to "challenge my friends" to a "contest of speed" on my bike, that's fine. It's not fine on motorcycles or cars. People have been comparing times on roads for the full history of the bicycle. People have been blasting down hills as long as I can recall. Strava hasn't changed the existence of informal competition; it's just facilitated it.
Strava does host competitions they initiate, however. These competitions are never for the fastest time descending dangerous roads. They're typically who can climb the most feet, or ride the most miles, or do a climb from a famous race the fastest. There was no such contest for South Park Drive, obviously. If Kim tried to go fast on South Park, it was by his own choice. The irony is if he were still alive I'm sure he'd be the first to deny Strava had any liability in his crash. The last thing he'd want is for the future of Strava, which he obviously loved, to be put into jeopardy by liability concerns. This is a nakedly cynical move by his family to exploit his tragic death, at the expense of an activity he obviously loved. People have been dying on bikes since 1842. They will continue to do so, whether or not they're subscribed to Strava. This is unfortunate, but it's a risk we willingly take every time we get on our bikes. On the other hand, Strava should think twice before opening a category for motorcycles... but they've known this all along.