Charlotte McKinney did NOT choose to share her boobs with the world -- instead she was the victim of hackers ... according to her rep.

On Wednesday night ... a topless pic was posted on her Instagram -- instantly grabbing the attention of her 500,000 followers. It included the caption, "I'm gonna be so damn hungover tomorrowww" -- making it seem like she'd just wrapped a night of drunken fun, and decided to get naked for fans.

But her rep tells TMZ ... "Charlotte has once again become a victim of hacking. It is disgusting someone does this and hopefully laws will change to protect people from these cyber attacks."

The topless shot was taken down early Thursday morning.

See also

Kate Hudson -- On a Topless Beach! Punks Out (PHOTO)

10 NSFW Moments From Rihanna's 'Bitch Better Have My Money' Video -- See The Topless Insanity!

ncG1vNJzZmivp6x7tbnZZ5qopV9nfXKBjmluaGhpZLCprdGlpq2slWK6pLfIp6WesV2drqS3xJ1kraegobK0v4ypn6isn2K2r7%2FTmp6rmZ1k