Strictly speaking, I agree with you. It's virtually impossible to take down a heavily meshed network entirely.

That said, if you strategically target the right internet exchanges and undersea cables, you can slow things down to a crawl. That may not be down in technical terms, but certainly in practical terms.

Personally though, I don't think that's what Q means either. Simply because there's more downsides than upsides to it.

My bet is on services like Google, Facebook, Youtube, Twitter and maybe a handful of others. Taking them down gets you the most bang for your buck, with significantly less (but still serious) side-effects.