Kristen Bredehoeft -- star of A&E's show "Flipped Off" -- went on the attack this week after her ex-boyfriend blasted naked pics of her all over the Internet, TMZ has learned.

The TV star was none too pleased Monday when she spotted a XXX Internet post made by her ex-beau and the caption, "I have a ton of naked pics of Kristen Bredehoeft and will be posting a few each day. I also have a sex tape she doesn’t know about so keep checking back."

Bredehoeft immediately took action and sent in her legal team to do damage control, threatening to sue her ex if he didn't take down the nudie pics ASAP.

We're told the guy got the message loud and clear because he quickly axed the posting and replaced it with an apology that said, "Sorry for the inconvenience."

Sources close to Bredehoeft tell TMZ ... she does not take the situation lightly and will take harsh legal action against anyone who posts the pics on other sites.