Or from New Orleans. Except in N.O. I'm not sure they knocked - other than knocking the doors down when no one answered and then proceeding to take every weapon they could find. I know one thing - if my department had sent me down there to help out during Katrina, and the people in charge would have sent me out on some type of witch hunt like they had, I would have refused to go along with it. Or if they put me in charge of a team of like minded LEOs we would have come back empty handed - "Gee chief, every house we searched didn't have one single gun. We'll try harder tomorrow."They must have gotten this idea from Janet Reno.

We do the same thing here in Dallas... and have been for several years. It's called "knock and talk" community policing and it's held up to court challenges. A team of officers (6 to 12) goes into a crime ridden apartment complex where the management or neighborhood watch group has requested our help to run off the hoodlums. We know which specific apartments are causing the problem and we "knock and talk" to those occupants. The contact officer follows a very detailed script that has been approved by City & County attorneys, and that has also held up to court challenges. The entire conversation is recorded to prevent all of the "he said, she said" controversy.This is very scary stuff. It is hard to believe that their District Attorney would allow this kind intrusion to individual privacy.
I am constantly stunned by the idiots that always let us in and then pretend that they're shocked when we find all the guns, drugs, and other contraband. Guns alone are not an issue but most of the people we find in these places are felons and they cannot posses them. I guess in a way it's not surprising though - these people aren't the brightest bulbs on the strand - that's why the live the life of crime that they do. We even had one moron that had been arrested several times during these operations tell us, "My attorney keeps telling me not to let you guys come in and I won't keep getting arrested so much." When asked why he let us in he said, "I don't know - I guess I'm just stupid." I don't recall anyone arguing with him about that point.
It really doesn't matter whether you agree or not with the law regarding warrant-less searches. What really matters is all the innocent law abiding people that live in these complexes and neighborhoods and are at their wits end in dealing with the criminals that live around them. When they call us they beg us to do something to help them out so that they and their kids don't have to be surrounded by these thugs and open criminal activities. We constantly try and come up with options to deal with it and these "knock and talks" have helped some.
Lots of people I share this with find it hard to believe that there are areas of crime infestation like this. They can't relate to it because they've never been exposed to it, or if they were, they would just move away before it got to be this bad of a situation. I know I would (and have) done exactly that over the years.
In conclusion, if the police came to my door and asked to search my house I would ask them why they wanted to (just to find out what their reason was - what was causing this level of police activity that probably was costing their department a lot of money) and then tell them nope, but to have a nice and safe day - end of conversation (at least on my part). I've found that most people (at least the law abiding ones) are fine with why the police are conducting these operations once you take the time to tell them the reason why. Understandably people get concerned when they see a large team of heavily armed (several member usually have AR15s or shotguns with them - we've been shot from doorways and windows as we walk through these complexes) officers walking through their apartments. They usually are concerned that we're looking for some murderer or carjacker but calm down once we tell them what we're doing. Heck, they'll even point out additional apartments we need to focus on because of their specific knowledge of criminal activity that's occurring there.
Anyway - just me 2¢s worth on this topic.