And btw, devices that read your fingerprint with a secure back-end are no longer fiction and it is probably just a matter of time until this technology is used for online verification. 10 years ago people would object being treated as criminals, but in the end it will happen. It's already standard in some countries when you apply for a passport to take you fingerprint, electronically. Ultimately, everyone's ID and fingerprints and locations are being recorded and categorized. We are going to live in a safe world, and if anyone manages to fake an ID, someone sure gets screwed beyond hope or justice.
Neither does a car, but yet people trust their cars and that the breaks work, or that the driver behaves prudent.
Anyway, it is just an idea. I think some reasonable ID verification might be good enough to justify an Oracle account upgrade, provided such option exists, to allow people to upload pictures.
According to Jive Documentation, when there are exceptions to the rules you've defined, you can create user overrides. User overrides provide a user-by-user way to express those exceptions. You might be further limiting the user's access, but you could also be broadening it, such as to lend an administrative flavor to the user's access.
The table shown in the Custom Permission Levels and User Overrides for Spaces shows specific access writes of certain groups. It shows an "insert image" option. How and whether or not it works, or whether it only works in combination with default groups, I don't know, but it looks promising.
Anyway, this is just a forum and fingerprints are not necessary to address anonymity for the purpose of posting screenshots and avoiding spam or unsolicited content. There are other reasonable ways and it seems the forum software provides the option to assign requried privileges.