NBA Star Matt Barnes SUED Over L.A. Rear-Ending

Former L.A. Lakers star Matt Barnes is being sued for $25,000 minimum -- after allegedly rear-ending a car on an L.A. freeway last year ... and causing the family inside injuries.

The family just filed a lawsuit against the NBA player, claiming they were driving on the Harbor Freeway in March 2011 when Barnes plowed into the back of their car.

According to the lawsuit, there were 4 people total in the vehicle Matt allegedly hit -- including 3 minors -- and all were injured during the accident.

Now, the alleged victims are demanding unspecified damages for medical bills, property damage, and more -- totaling $25,000 at the very least.

It's the latest legal headache for the basketball star -- you'll recall, Matt was arrested just last week in Manhattan Beach for an outstanding traffic warrant and resisting arrest.