First, this is not legal advice.  I made a poster.  I am not your lawyer or giving you any advice whatsoever.

This poster is essential to those who live with others.  Whether those people are your roommates, parents, or some other shared living space – these persons can give permission to the police to search your space.  That means that they can search your computer(s), hard drives, phone or anything located in your room.  Think about that.  Unless you have a password set on your computer and your hard drives encrypted, someone other than you can give permission for the cops to search your devices.  If your computer and hard drives are encrypted, that commands a “reasonable expectation of privacy.”  However, why create that possibility.  I created this poster so that no one can enter your room without your permission.  In some circumstances, this may not be bulletproof (dorms, hospitals, mental hospitals or other legally contracted space), but it will clearly demarcate your space as private and needing your permission to enter.  If you say no, they need a warrant.  Hang this up outside your room.

The small print at the bottom of the poster states:

The expectation of privacy that one has in his or her room is one that “society is ‘prepared to recognize as legitimate.”  Moreover, the subjective expectation of privacy one has in one’s room, house, dorm, or other area is clearly marked by the placement of this poster.