CALIFORNIA: i am an unauthorized subtenant who has been paying half of rent and utilities to my roommate/unofficial landlord since october. recently, he moved his sister in without notifying me and she sleeps on the couch and it makes me extremely uncomfortable to go down there. to be clear, i am not just renting a room. i have access to the whole apartment including kitchen and common areas etc.

for my safety, i set up a camera in my room. today while i was gone, i got an alert and saw that his sister entered my bedroom while i was gone without my consent. she saw the camera, got scared, and left. what can i do legally about this?