Any publication that is out of print, it's no longer protected by copyright for one IIRC.
- That also, we have users from around the globe, and that copyright across boarders is variable and complex.
- That postings typically snap an image from a user manual etc, which is to assist for non-business purposes, and has no material cost to the publisher (as opposed to the for-profit distribution, or profit loss of an organisation)
- That things are for ad-hoc fixes, not a 'library of free resources'.
... are all considerations, but due to the legal complexity, and the micro-nature of our forum debates, it's a Tc's and C's issue about a 'fair use' policy - to effectively put in place the necessary framework, but removing the need to 'police' per se.
For matters concerning forum admin, whereby reasonable duty is made to prevent copyright infringement, strong enforcement would likely significantly alter the forum value, preventing posting would be near-impossible to enforce without a blanket ban (again would cripple the forum), and that this is likely a matter for the top level forum admin, not you guys looking after the sub-forum (as far as rules go). As a 'community' is is reasonable to expect that people conduct themselves in an appropriate manner, and because it is done, forum moderation can be light-touch, as it is.
My view is that many would be in technical infringement, but that the practicalities would never lead to any sort of legal escalation, as we are a very small fish in a gigantic ocean, a really really gigantic ocean. As a non-legal expert, my views on the typical 'fair use' Ts and Cs of a forum such as this is that they should state 'images must only be posted if they do not infringe copyright laws'. And that the practical monitoring ability would be that any picture that includes a clear copyright or trademarking would be deleted, with the user PM'd to explain why (or you have a mecanism such as a tick box upon posting that declares 'any images are not knowingly subject to copyright').
Zip files and links to clearly copyrighted material should not be posted on the open forum, as would be my guess.
The PM facility should be used for inter-user communications where appropriate, especially for views that should not be expressed on an open source forum such as this.
Unknowingly posing an image that may be technically copyrighted is an altogether different thing to deliberately distributing content that you would normally have to pay for, and I would look at it like an inadvertent breech of a posted speed limit by a couple MPH, rather than openly driving 120MPH down a public road.
2012 I-MIEV Keiko Silver 11K
2010 Insight ES-T 43K
2001 Accord Type-V (F23 manual)
2009 Hornet CB600F