Posting a link - or a partial quote from the link - or the full text plus the link (OTT?) - I don't really have a problem with all these. Why can't people have a little bit of freedom? - just so long as it's not offensive or disruptive...
...but bear in mind copyright issues, in some instances (don't think it applies to anything quoted on this forum though).
But with youtube - yes there are some issues, especially seeing as for me it's blocked in its entirety at work (as, I imagine, it is for many others). A while ago we had embedded youtube which caused extra problems - it meant entire threads locked-out. I believe it was I who complained to Shaun - he ran a poll and then dropped the idea - for which I'm grateful.
Some forums, if you post a bald youtube URL, run a 'fetch' from the site and then display the movie title - which by-passes the block and is more informative than just a youtube reference number. Can this be done here on vBulletin, perhaps? Maybe an answer to one of FF's gripes.