I really want to just go put something under the wheels but I’ve never talked to these people.
Update edit: thank you for all the replies. I went over and knocked but no answer. It’s definitely not chocked. If I see them come home I’ll go back over. I’m worried as soon as the weight shifts loading it that it will just go down the hill.
The neighbors across the street would learn the hard way that other people need to chock the wheels on their unattended trailers
Yours is the obvious correct answer, yet people like OP still have to ask?