This is totally weird, this company came up with an idea where you knock on the window a certian way and it will unlock the door for you. This reminds me of the story about the “server knocking” where you have to “knock” on the server a certian way over the internet (link pinging or telneting to specific ports in the correct order) in order for the SSH or telnet port to open so you can gain access to the server.

They Don’t Call Them Knockers For Nothing