Vandalism or littering allowed?

Inserting flyers into people’s doors and gates is not vandalism and not littering. Ok, I accept that. Is it trespassing when they are not wanted? It is public nuisance when the owners would have to make the effort to throw them away? Is it a fire hazard when too many are left around and a lighted cigarette could set them ablaze? Is it a security risk to the owners when the flyers are a tell tale