A committee of elected lawmakers from a dozen countries investigating the spread of online disinformation and election meddling wanted to hear from Facebook CEO Mark Zuckerberg and COO Sheryl Sandberg at a hearing in Ottawa, Canada Monday.

Instead, the International Grand Committee on Big Data, Privacy and Democracy was sent Kevin Chan and Neil Potts.

Haven't heard of Chan, Facebook's public policy director for Canada, and Potts, the company's global public policy director? You're not alone.

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"We're told you're not even in the top 100" executives at Facebook, said Canadian Member of Parliament Bob Zimmer, the committee's co-chair. The CEOs of Google and Twitter were also invited and declined to appear. But the committee's frustration was reserved for Facebook, whose top executives have now twice stood up the lawmakers representing a combined 400 million people.

A November 27 hearing in London produced similar condemnation when a lower-level executive was sent by Facebook.

In this case, the Canadian contingent voted to summons the top Facebook executives, officially deciding that they will be called to Parliament if they ever travel to Canada.

"Should Mr. Zuckerberg or Ms. Sandberg come to Canada for any reason, for a tech conference or to go fishing, they should be served a summons," said Charlie Angus, a Canadian Member of Parliament. Zimmer said if that doesn't make them show up, the next step would be holding them in contempt of Parliament: a first for any American.

For their part, Potts and Chan defended the company's decision.

"Mr. Zuckerberg and Ms. Sandberg have entrusted us, we are subject matter experts on these areas," Potts said.

Potts and Chan were grilled on issues ranging from the infamous election consulting firm Cambridge Analytica — which they said they were not well-versed on — to a recent doctored video that slowed U.S. House Speaker Nancy Pelosi's speech, and a flagged, but not removed, post in Sri Lanka calling for explosives to be used to kill Muslim women and children months before bombings did just that.

Throughout the hearing, the fact that it was Potts and Chan answering questions, instead of Zuckerberg and Sandberg, was the repeatedly addressed elephant in the room.

"Mark Zuckerberg's persistent refusal to appear in front of this committee shows he does not want to be held to account for the record of his company, nor even to engage openly in the debate about the future regulation and oversight we need in this sector," the committee's co-chair, British Member of Parliament Damian Collins said after the hearing.