[Merrill]

Widespread use of this technology would be a problem for government, since it would be difficult to insert fake records to create "legends" for undercover detectives, spies, and people in witness protection, etc.

[schoen]

Widespread use of Facebook might have a much more significant effect, because people don't usually memorialize all of their life events in a public digital notary service but often do so with social media.

I bet counterintelligence agencies are scraping social media and the web in order to see whether some travelers' identities are lacking in (or contradicted by) historical online documentation.