I`m not sure exactly how the spam function works at myspace but I`ve always assumed it was a forward that an admin type could look at and see the offending message. It`s usually fairly obvious what`s going on in those types of messages on myspace, hell half the time it`s the same message over and over again. If the message is questionable, say someone is sending scuba related spam thinking that a forum like this wouldn`t consider such a targeted groups spam, you could simply warn them. Self policing by members is how ebay does most of its work.