Yes, this thread certainly is still relevant. If you want to start your reading on the subject with regards to US law, the Wikipedia article Section 230 is a good place to start:
https://en.m.wikipedia.org/wiki/Section_230
Without section 230 protections or some equivalent, many small sites that publish user provided content might have to close. FB, twitter and the like would also have big problems because of their size, but the scale they operate at would be a double edged sword that also HELPS them.