By now it's common knowledge that President Donald Trump has a habit of turning to Twitter when he’s not pleased. Trump took to the platform Friday to post a picture of Democratic Sen. Chuck Schumer standing alongside Vladimir Putin.

“We should start an immediate investigation into @SenSchumer and his ties to Russia and Putin. A total hypocrite!” the president wrote.

Trump also used Twitter to voice his thoughts on Attorney General Jeff Sessions, who recused himself from an investigation into the Trump campaign’s dealings with Russia after reports surfaced saying he met with a Russian ambassador without disclosing it.

In a series of four tweets Thursday, the president defended Sessions.

“Jeff Sessions is an honest man. He did not say anything wrong. He could have stated his response more accurately, but it was clearly not intentional. This whole narrative is a way of saving face for Democrats losing an election that everyone thought they were supposed to win. The Democrats are overplaying their hand. They lost the election, and now they have lost their grip on reality. The real story is all of the illegal leaks of classified and other information. It is a total “witch hunt!”

Cybersecurity experts have voiced their concerns about Trump’s constant tweeting, citing the possibility of being hacked or tracked by foreign agencies.

“We’ve never had a president that’s shared so much of themselves, not just what they’re saying, but their psychological tics in such an overt manner,” P.W. Singer, a defense expert told Politico. “And you can be sure that foreign actors are studying that, too.”

The American people are wary of Trump’s tweeting, as well. A January NBC News/Wall Street Journal poll showed that 69 percent of respondents thought Trump’s tweeting habit was a bad thing. Campaign staffers also revealed they’d tried to lure the president away from constantly updating his social media, noting that they attempted to show him positive coverage to prevent him from tweeting.

“He sends out these tweets when he feels like people aren’t responding enough for him,” a former campaign official told Politico.

While Trump has continued tweeting into the third month of his presidency, it appears he’s at least slowing down. During his campaign, Trump tweeted an average of 15 times each day, according to an analysis by the Boston Globe. As president-elect, that number was down to about five times per day. In the final week of January, Trump tweeted an average of four times per week.