That isn't how an open house works (at least in my experience buying a house in Los Angeles in 2018). They advertise the hours, put up a bunch of balloons, and

That isn't how an open house works (at least in my experience buying a house in Los Angeles in 2018). They advertise the hours, put up a bunch of balloons, and anyone can walk in. They ask you to sign a sheet so they can contact you, but I never saw them make anyone sign it or request an ID. I visited maybe 30-50 houses doing open houses, and a good half of those weren't with our realtor (or they arrived well after we did).