Good point, can't find the presentation about emberjs performance right now, however this one highlighted a couple of times: do not create unnecessary views :-) The issues I'm seeing with this global js is say user is on her homepage and then she clicks another link, e.g. user profile. As we are using push state we won't refresh the entire page and if that second page has youtube links they won't be wrapped with this script, it fires just once after emberjs initialisation. As an obvious workaround we'll have to setInterval to 100 or 500 to overcome this, which is not really great. Or handle all transactions, which will lead to a duplicative code.

I'd say: for the time being let's create a separate view, which is definitely will affect the fronted performance (have never measured it though), however will avoid headaches of dynamic events and stuff.