Blac Chyna's firing a warning shot at her former side piece -- telling him if he rips a page out of Rob Kardashian's playbook ... it's gonna cost him dearly.
Powerhouse attorney Lisa Bloom sent Ferrari a letter -- obtained by TMZ -- warning him not to sell or post any nude pics or images he might have of her. Bloom says, "Posting online or distributing photos of Ms. White's intimate body parts is a crime punishable by fines and jail time."
And for good measure ... she also brought up California's revenge porn law. Remember, Ferrari already came within a nipple or so of semi-nudes ... when he posted pics of himself and Chyna in bed.