[RHSeeger]

It certainly seems like it applies to a lot more than youtube to me, including comment boards. Looking at the wording in teamhappy's response to you (which I cannot reply to)

> one of the main purposes of which is to store and give access to the public to copyright protected works or other protected subject-matter uploaded by its users

That sounds like it includes comments by users (since their comments would be automatically copyrighted)

> the content is uploaded with the authorisation of all rightholders concerned

The owner of a comment board has no way of knowing if their users will include (in their comments) content to which they don't have the authorisation to do so.

It seems pretty clear to me that it applies to comment boards.