Checking social media accounts is a tricky one imo.
On the one hand, I'd be outraged to be asked to supply this information and would almost certainly refuse.
OTOH it's not a bad idea to weed out dodgy applicants.
Of course whether mermaids are looking to weed out dodgy applicants or bad faith applicants or applicants who have liked the wrong tweet is anyone's guess.
DD1 has recently applied for a teaching assistant job, not in the UK. She had to supply her social media. She's a very sparing user of social media anyway but she unfollowed me on a twitter in advance of sending in the information as she said she couldn't risk being seen to follow me although that might have been a handy excuse since she has graduated with a degree in wokery.
Thing is, I think we can all agree that there are some people in safeguarding sensitive jobs who need their hard drives looking at. On the other hand the big brother side of it appalls me. And of course any sensible applicant will do as DD did and have deleting purge before submitting.