I read "post vacation photos while on vacation" as "signaling I'm not at home and a good target for burglary". I tend not to tell anybody that I've taken a trip until I've returned home.

Posting vacation photos to social media when you're actually on vacation is a bad idea. You're signaling to people you're not at your residence or job, which is bad security anyway.

Save all the cute pictures to post when you get home.