Is it insurrection?
When an agency of government openly and wantonly uses armed force in a manner which is expressly contrary to the laws and powers of the superior government, what else would you call it?
No, I don't believe so. Insurrection is defined as an organized rebellion against authority. The perpetrators would be known as rebels.
The city officials of New Orleans are not organizing to overturn authority, but rather in conjunction with the NG and LEO from outside their state (and I'm sure the BATFE is probably there as well) are overreaching their authority by violating at least the first five Amendments of the Constitution, and possibly others.
True enough I think, they have certainly ignored the "authority" of the Constitution, but they are not engaged in an organized rebellion to overthrow the government.
Also, I believe that the lawlessness which began within the city after the hurricane had passed does not qualify as an insurrection. That was just good old fashioned criminals and thugs (along with some worthless NO Police apparently) taking advantage of the situation because there was no effective law enforcement in place to stop them. But I wouldn't say that they were organized rebels attempting to overthrow authority.
Again, I await the response of our elected officials to address this, even amid the unlikely hood they will.
Here is something posted a few times on fr that describes the Constitutional violations.
1st Amendment: NOPD and National Guard are confiscating cameras and film from reporters and not allowing pictures to be taken.
2nd Amendment: police and NG are searching homes and confiscating legally owned firearms.
3rd Amendment: National Guard are staying in hotels, churches, stores and homes with out permission of the owners.
4th Amendment: Warrantless searches of property and seizures by police and NG.
5th Amendment: Seizure of property without due process of law.