I haven’t heard of huge numbers of users quitting Facebook over its recent experiments and I haven’t heard of any court cases on behalf of one or more users yet.
That could mean that from now on, Facebook will be free to do exactly as it pleases. If that ticks off or disadvantages its users, those users take responsibility from now on as their continued use of Facebook in spite of all the publicity about what Facebook has been up to can surely be seen as informed consent.
Understandably, the scientific community appears to be appalled.
On this side of the big pond, a UK regulator is launching a probe into the experiment.