Just register the copyright on things that you expect Meta to use. Registering a copyright is cheap and gives you the right to sue for triple damages for any infringement after the copyright is registered. You must have a registered copyright to sue, if you register the copyright after the infringement you can only sue for actual damages.

Consult a real lawyer if this matters to you. The above is my understanding of the law, but I'm not a lawyer and different countries have slightly different laws.