We have had an issue with a new member using private messaging to send out spam. If you receive messages that look like spam, especially from recently subscribed users, remember you can use the report feature
to send the site staff a notice. This will send a copy of the message to the site staff so we can deal with the issue.
This also works if you notice spam in the forums and we haven't cleaned it up yet, we do try to get it before anyone sees it.