One thing that drives me crazy is that people deliberately post stuff that used to be (semi-)private for the whole world to see and then go full state-secret about stuff that used to be (semi-)public.

In the not so distant past, a big book of street addresses and phone numbers of everyone in town would show up on my driveway every year. Now people think they should burn their computer and start over from scratch because their email address showed up in some database in Estonia.