I'm one of those rare people who never signed up to FB, and I never will; I have no desire to reconnect with people I left behind in my schooldays, I'm not interested in where people go on holiday or what they're having for tea, and if I want cat videos, I imagine I can find them on YouTube. On that basis, FB never appealed to me.
The recent scandals about personal data and how its used have confirmed that I made the right decision; and if I had any doubt, a recent work meeting with a company who specialise in using the FB algorithm to target potential employees has removed it - the level of targeting and specificity they can achieve by using the data that FB harvest about its users is genuinely sinister. The guy actually said to me, "the reason FB is free to users, is because you're not the customer - you're the product." Scary stuff.
That aside - online abuse does seem to be reaching epidemic proportions; and the social media companies appear to be moving heaven and earth to ensure that they don't have to take any responsibility for the content that appears on their platforms. My suggestion - set a date, and turn off FB, Twitter and Snapchat; the latter being, as far as I can see, inherently dodgy, since it's USP seems to be that messages disappear immediately having been read, hence it's popularity with 'the kids.'