Stop us if you've heard this one before: Lindsay Lohan was out partying this weekend and blah blah blah police.

Seems Lohan was at a nightclub in NYC when she made the acquaintance of one Christian LaBella, an employee of an Illinois congressman and celeb hanger-on whose Facebook page is loaded with photos of himself with societal pillars like the Kardashians and VP candidate Paul Ryan.

When LiLo and her pals went back to her hotel room to continue the festivities, LaBella tagged along -- and that's when the trouble started.

At some point, Lohan noticed LaBella had taken 50 photos and videos of her with his phone and was sending the evidence to pals. When she confronted him, he allegedly assaulted her, throwing her on the bed scratching her hands.

She then reportedly locked herself in the bathroom and/or ran out of the room but returned -- because that's smart -- and LaBella continued his attack on the perennial damsel in distress by choking her and pinning her to the floor.

Friends came to Lohan's rescue, and she pulled the fire alarm to keep the dude from using the hotel elevators. Cops later arrested him, booking him on two misdemeanor counts of assault and two charges of harassment.

Her rep told TMZ, "Lindsay was assaulted early this morning in a New York hotel. While she did sustain some injuries, she was not hospitalized. The assailant was arrested and is currently in police custody. Lindsay has spoken with police and is fully cooperating with the investigation."

Those charges have since been dropped, much to LiLo's artificially-inflated trout pout chagrin. Didn't her mother ever teach her not to invite strange men back to her room?

Oh wait -- we just remembered who her mother is. Never mind.