Hilary Duff just learned the hard way about the danger of posting vacation pics on Instagram -- it sets up her empty crib as an easy target for crooks on the hunt for high-end jewelry.
We're told someone broke into Hilary's Bev Hills pad late Wednesday. Someone broke through a door, rooted around and discovered Hilary's stash. The alarm never went off.
Our sources say the thief or thieves made off with bling worth hundreds of thousands of dollars.
Hilary and her fam were in Canada. She posted a bunch of pics and vids, making it clear she was out of the country. She's still there, so cops still don't know the extent of the heist.