Apparently we have upset a neighbor who was enough of an asshat to stick this to my car window (leaving a bunch of residue) with heavy masking tape.
Reader's note: Property manager supposedly pays for yard care, tenants are not responsible according to our lease.
If they had put this on the door to the house I'd be less upset.. aside from the tone and general ass hattery of the letter.. but it also made one of our roommates feel unsafe.