Nearly 100% of the spam is generated by new members. In most cases they just recently joined and have never left comments on other posts. These members always have zero model submissions.
If it’s not spam, then we see questions or group posts that make no sense. Either supplying completely insufficient information or asking for something that is way out of the normal context of GrabCAD. These posts usually become what I would refer to as a drive-by-posts. They create an account, ask a stupid question, and then you never hear from them again.
Then of course there are the usual inappropriate requests for homework, pirated software, pirated machine designs, etc.
Why does GrabCAD continue to allow new members to make posts to the groups and question sections? Maybe there should be some kind of vetting process. New member should be required to make posts and comments in a test group section and get approved before graduating to the adult section.