What exactly is forbidden, by who? I don't get the use of that word there.
Also, anyone who doesn't know the "before" and "after" search operators is missing out on some excellent nostalgia-trawling similar to what is described here.
"cat before:2007" -> 2005 to 2007, the OG cat videos
"skateboard before:2010" -> yes
"assange interview before:2016" -> then filter for longer videos
"parkour after:2009 before:2015" -> parkour videos from 2009 to 2015