As long as the public remains largely ignorant about 4th Amendment rights, police will continue to rely on coercive tactics that treat people as guilty until proven innocent:

Dallas police began a new initiative today to combat drugs. Citywide, officers are headed to suspected drug houses to "knock and talk" with the occupants.

The technique involves knocking on the door of a suspected drug house and trying to talk the people inside into inviting officers in to search without a warrant. Police can enter without a search warrant if they see illegal activity happening.

Dallas police have long used the technique, but its use will be widened during the next few months to include more officers and more areas within the city. [Dallas Morning News]

If this sounds to anyone like a program that only affects drug offenders, it's not. Police tactics like these are always framed as an effort to "get weapons and drugs off the street," but they are so much more than that. By definition, the people targeted under such policies are innocent citizens against whom police have no actionable evidence of criminal activity. After all, when police have credible facts indicating that drug crimes are taking place at a specific location, they may obtain a search warrant and enter lawfully.

The "knock and talk" approach is used exclusively to enter private residences in the absence of probable cause. Vague and unfounded suspicions, or even prejudices, could ultimately determine which locations are singled out for investigation. In the process, innocent people living in high-crime neighborhoods are placed at great risk of arrest in the event that a guest, neighbor or former tenant left something illegal on their property.

As misguided as these tactics are, there is one simple option available to concerned citizens who don't want police digging through their drawers: just don’t let them in. Unless you give them permission to enter, police need a warrant to search your home. You may simply decline the search and tell the officers that you'll gladly cooperate if they return with a warrant. If that makes you uncomfortable, another option is not to answer the door at all, which also reduces the likelihood of police claiming that they saw or smelled something illegal when you opened the door for them.

The bottom line is that invasive "knock and talk" programs don't work if everyone knows their rights, which is why the D.C. police simply canceled theirs after we started doing this:

Anyone in Dallas who's concerned about the new policy should consider organizing a similar effort.