I live in LA and all this is breaking on KTLA.... seems like she's finally flipped her shit.
Other updates from TMZ:
Cops Called to Brit's House for "Custody Dispute"
Posted Jan 4th 2008 12:36AM by
TMZ Staff

TMZ has confirmed that LAPD has been called to Britney Spears' house in Beverly Hills for what we're being told is a "family custody dispute."
LAPD tells us the call came in around 8:00 PM PT this evening, but they would not tell us who made the call or what the specific problem was. Officers, we're told, are still on scene.
Spears, who was nearly two hours late for today's scheduled deposition in her custody case, was reportedly scheduled to have her sons tonight until 7:00 PM.
Story developing ...
UPDATE:
Us is reporting K-Fed's bodyguards went to pick up Sean and Jayden at Britney's home this evening after her scheduled visitation, but Spears refused to turn the kids over. Police were then called. Britney's soon-to-be ex- attorney Sorrell Trope told the mag, "In a normal case when someone shows up with a certified court order saying the kids need to be somewhere else, the police see to it that the order is obeyed. But that is in a normal case."
More Cops, Ambulance Now at Spears' House!
Posted Jan 4th 2008 1:24AM by
TMZ Staff

Holy Kramer vs. Kramer!
TMZ is at Britney's house in Beverly Hills as several more police cars, fire trucks, an ambulance
and a police chopper have now all descended on the popwreck's humble abode. Don't let 'em git me!!
We've learned Spears has refused to turn her two sons back over to their daddy tonight, as ordered by the court. LAPD tells us they've been called to the home to deal with the family custody dispute.
Keep refreshing for more details!
I'll keep writing updates as I hear them on the local news.