Recall that Echelon records and archives every electronic communication. Land lines, email, cell phone, etc. Forever. If someone is identified, all their communications can be retrieved. Future calls can be tagged for review, either by software or human intervention.
It used to be that our benevolent government would have to ask the Canadians, Brits, or Aussies if they had anything on so-and-so in their files. Maintain deniability, so to speak hell no, were not spying on Americans! Foreign nationals would retrieve and forward the requested information. I suspect the keyan commie has dispensed with that step.