From TMZ:

We now know why there is a warrant out for Lindsay Lohan’s arrest.

Sources tell us the honchos from the alcohol education program in which Lindsay is enrolled notified the court on Friday because she was not complying with the terms of her probation. We’re told the violation does not involve an alcohol test, but rather enrollment in the program.

We’ve also learned Lindsay has a new lawyer, Shawn Chapman Holley , and we’re told her new lawyer will fight the warrant, arguing Lindsay has not violated any term of her probation.

UPDATE 3:40 PM ET: The cops now tell us they were called for a disturbance and not there to arrest Lindsay.

Sam and Lindsay have gotten into a nuclear fight at Sam’s house. The police are at their front door to talk to Lindsay and Sam but they will not open the door. The two are definitely still in the house.

We’re told the police are trying to serve Lindsay her warrant.

UPDATE: 3:49 PM ET Three LAPD cops were knocking at the door, trying to get Lindsay and Sam to open it but they would not. One of the cops was pacing the property. The cops have left the front door but they’re still in the area. One of the cars left the house but is parked up the street. Word is they may arrest Lindsay and take her to jail.

UPDATE: 4:20 PM ET Here’s the latest. The cops have left the house. We’re told the LAPD will not arrest Lindsay for the warrant, at least not now. Sources say Lindsay will not surface until the court hearing on Monday. If she does go out in public and cops see her she risks getting arrested. So it’s unlikely she will show her face — if she’s smart — until Monday AM.