>Posting visual propaganda made by others hardly counts as "speech"
Not sure what ya mean by broader sense, but pretty sure I strongly disagree with the premise.
Just because I am not the OC of meme or vid, doesn't imply I can't agree with it's message, or use it, even edit it to send a new message of my own.
A board dedicated to OC is a great idea, but would be very small as most people do not have the time, skill, or creativity to make their own content. They sift through hours of vids and gigs of memes, discarding most and latch on to those few that speak to them. And due to the very nature of ideas and memes, you would quickly find many could and will lay claim to OC as their idea first or stolen from someone else.
Even the ideas of ideas are not original as you might think. Nearly all original creations are merely copies and transformations and combinations of earlier ideas "Everything is a Remix" If you have never seen this please watch
It pertains mostly to movies and music, but the remastered version here even touches on memes as we know them now
If you dont feel like a 40min video at this time then just skip to 20:45 to see examples ideas not being wholly original, or
22:45, that illustrates my point of memes being re-invented
>“I invented nothing new. I simply assembled the discoveries of other men behind whom were centuries of work. Had I worked fifty or ten or even five years before, I would have failed. So it is with every new thing. Progress happens when all the factors that make for it are ready, and then it is inevitable. To teach that a comparatively few men are responsible for the greatest forward steps of mankind is the worst sort of nonsense." ― Henry Ford
If /tv/ ever really takes off, I think some threads of remixing will be a great addition