Dear km2pb, I have reverted your edits in which you re-added links to 3rd party Youtube URLs. Whether or not these "make the map more interesting" is not the question here; they don't belong in OSM. I have not sufficiently made this clear in my message to Hubert above, but I am saying this in my capacity as a member of OSM's Data Working Group and I sincerely ask you to stop adding links back in that I have removed (or in fact add any links to 3rd party platforms apart from the well-established Wikipedia links). 
