I think if you're going to undertake large-scale chaffing of the internet, it'd be way more fun to target the future rather than the present.

Don't just create a hundred million fake profiles with their own social networks: try to create alternate timelines. Profiles on social networks, emails, instant messages, dating profiles, recontextualized and faked photographs, websites and DNS entries and forums, all supporting an alternate timeline, smushed as thoroughly as possible into the internet.

Don't just try to confuse current surveillance states, try to confuse future historians!