President Trump, who reportedly disclosed highly classified information to top Russian officials last week, has long used other people’s indiscretions with secrets against them. He’s demanded investigations into the “leakers” he thinks are undermining his presidency. He wielded Clinton’s private email server scandal like a sledgehammer against her during the presidential campaign, at one point insisting he would “lock her up” if elected. (He hasn’t yet.) But even amidst all that, Trump once took an even harder line on disclosing classified information to foreign adversaries.

In the summer of 2013, former National Security Agency contractor Edward Snowden leaked a massive trove of classified U.S. information to British and American journalists. The documents revealed secret mass-surveillance programs run by the U.S. government and allied countries, sparking widespread political debate and investigations throughout the West. Their disclosure also made Snowden a fugitive from a wrathful U.S. government. Shortly after leaking the information, Snowden fled first to Hong Kong and then to Moscow, when he resides to this day under temporary asylum protections.

Trump, a private citizen at the time, frequently commented on the news of the day on Twitter. The NSA disclosures were no exception. At first, Trump used the episode to express his ire towards the Obama administration embarrassing the U.S. on the world stage. But after Snowden’s flight to Russia, his anger on Twitter turned towards the former NSA contractor he described as a “traitor.”

In case the underlying message of those tweets was too subtle, Trump made his demands explicit: Snowden should be executed if he returns to the United States because he had, according to Trump, “disclosed serious information” to Russia and China.

It should be noted Trump wasn’t without mercy in this case. If Snowden could reveal Barack Obama’s “records”—perhaps the president’s “real” birth certificate, for example—Trump said he might become a “major fan” of the former NSA contractor.

Snowden, for his part, remains in effective exile in Russia. He didn’t endorse Trump, but he was also no fan of Hillary Clinton during the presidential election, at one point describing the race in a now-deleted tweet as “a choice between Donald Trump and Goldman Sachs.” On Monday, however, the irony between the U.S. government’s pursuit of him and the current president’s loose lips was too much for him to pass up.