Not to be outdone by Facebook co-founder Dustin Moskovitz’s announcement last week that he and his wife would donate $20 million to pro-Democrat and pro-Clinton groups, LinkedIn co-founder Reid Hoffman said Monday that he would donate up to $5 million to non-profit groups that aid veterans if Donald Trump releases his tax returns by Oct. 19, the date of the final presidential debate.

Like Moskovitz, Hoffman took to Medium to announce his pledge, which was inspired by the story of a 26-year-old Marine Corps veteran named Pete Kiernan who had set up a crowdfunding challenge on Crowdpac to raise $25,000 to be donated to non-profits like Team Rubicon, the Special Ops Warrior Foundation, and the Yellow Ribbon Fund if Trump released his tax returns by the last debate, which will be held in Las Vegas.

Spurred by the idea, Hoffman offered to give five times whatever Kiernan raised, up to $5 million, if Trump unveiled his returns. Hoffman writes on Medium:

In 2012, Donald Trump called President Obama “the least transparent president in the history of this country.”

Then he offered to donate $5 million to charity if President Obama would release “his college records and applications” and his “passport applications and records.”

He adds:

[T]aking Trump’s own 2012 offer to President Obama into account, I’d like to assist Kiernan in his campaign. If Kiernan’s campaign hits or exceeds its target, I will match the total amount he reaches with a 5x contribution, up to $5 million.

Hoffman’s push is not that of a simple disinterested citizen. He’s donated millions to democratic candidates and groups, as well as the campaign finance reform Super PAC Mayday PAC, according to records collected by the Center for Responsive Politics.

 

Hoffman’s dare to Trump is twofold: Releasing his tax returns will let Trump avoid being called a hypocrite by being as un-transparent as he’s accused President Obama of being; and it will help veterans, a group to which Trump has pledged his support. “Given Trump’s vocal support of veterans, I imagine he will recognize the great good that can come from Kiernan’s proposal,” Hoffman writes.

Trump has said that he needs to keep his returns private because of an ongoing IRS audit, a claim that Hoffman has pooh-poohed as little more than gamesmanship. He says:

What this means, of course, is that there’s no real reason that Trump is keeping his returns secret, except that he sees them as a bargaining chip to utilize.

Kiernan’s Crowdpac drive, which now is looking to raise $1 million, has so far received about $65,000. Should it reach its goal, handing over the $5 million should not trouble Hoffman’s finances too dearly. His net worth is $3.8 billion according to Forbes, aided by an $800 million jump in the value of his LinkedIn lnkd shares after Microsoft msft announced in June that it was acquiring the career site for $26.2 billion.