That is an interesting thought. At any moment, an officer that can't get a search warrant could anonymously call 911 from a burner cell or pay phone and report a violent situation. That alone is enough for a full-scale paramilitary invasion of the target's home or office.
Doesn't even have to be violent. Just as easy to roll an informant to claim drugs dealings at a residence. Drugs seem to be easiest way to get a no-knock raid, even if your mayor.
