I have a filter set up on a view in Google Analytics to show the full hostname for pageviews. This enables us to analyse traffic on our various microsites.
However I'm also seeing pageviews recorded against external URLs e.g.
www.youtube.com m.youtube.com inst.webinstantservice.com
I could filter these out (or just ignore them) but I can't figure out why they're appearing at all since they aren't using our tracking code.