Fwiw, I had exactly the same thing happen a while ago at the University institute I worked at, via plain old email. There were some thefts from offices, and sev

Fwiw, I had exactly the same thing happen a while ago at the University institute I worked at, via plain old email. There were some thefts from offices, and several people started posting "watch out for strange persons" posts, including descriptions of the "strange people" that were clearly racist, to the institute mailing list.