To use this Overpass API server from Overpass Turbo, in "settings" in Overpass Turbo enter:
https://overpass.atownsend.org.uk/api/
The server only works over IPV6 and only via https. If you can see this page, you can access it via IPV6.
Only data for Britain and Ireland is loaded. It is updated with changes to OSM every night.
Areas have been loaded, so area searches work. There is currently no metadata (so searches by OSM user name won't work) and there is no attic data so searches by date will not work either.
Not for commercial use. If you need a commercial service, look elsewhere.
Don't do anything like the "problematic behaviours" listed here. There is no SLA, so don't complain if it is no longer available (temporarily or permanently). Downtime is expected for database reloads. Problematic users will be blocked, and if they obfuscate their origin it will result in the the server no longer being public for everyone else.
I am the only person that I've set up to have access to this server. If you request data then the normal Linux logs will record the fact. I can't comment on who might be watching traffic between you and the server (in Germany). If you're particularly worried about people NOT knowing I recommend that you set up your own server and serve everything from there instead.
Drop a message to SomeoneElse via OSM or Github, or discuss in the OSM forum.