A place to start might be this large, very popular list that combines a bunch of other lists: https://oisd.nl/
Actual text file is here (large file warning): https://hosts.oisd.nl/
Just prevent your service from shortening links to any of those domains.
This is an excellent merged blocklist, with public whitelist (oisd is fully closed, no insight in what is whitelisted and why, also causing more false positives..)
A place to start might be this large, very popular list that combines a bunch of other lists: https://oisd.nl/
Actual text file is here (large file warning): https://hosts.oisd.nl/
Just prevent your service from shortening links to any of those domains.