The problem is that the corruption has built up so much, and so many generations have grown up being "educated" by propaganda on TV like "Law & Order" that they think this is not corruption at all.
But the 4th amendment is clear, they need a warrant. They never get one. And when they do, they are almost all fraudulent/invalid warrants.
But since government is the only one that gets to enforce the laws, it is not a surprise that government tends to let government get away with criminal activity.