On Tuesday morning, President Donald Trump started out the day as he has in the past: by tweeting criticisms of the news media and courts that have blocked his travel ban.

But he also took time to block the Twitter account of VoteVets.org, an organization that represents around 500,000 U.S. military veterans and their families.

Trump first tweeted that the "Fake News Media has never been so wrong or so dirty" and accused journalists of using "phony sources to meet their agenda of hate."

VoteVets.org responded to Trump in a tweet that said, "You're describing your road to the White House to a T" and accusing the president of "colluding with an adversary of the United States," in reference to concerns about Russian meddling in the 2016 presidential campaign.

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Will Fischer, director of government affairs for VoteVets, told NBC News that he had written the tweets criticizing Trump when the account was suddenly blocked.

"He has no interest in hearing any type of dissent," said Fischer.

VoteVets.org has been critical of Trump before, most recently in a television ad featuring a veteran of the war in Afghanistan speaking directly to the president about stripping healthcare from vets.

"There’s not an issue being debated that doesn’t affect military families and vets," said Fischer. "There are nearly 2 million veterans and their spouses on Medicaid. 500,000 veterans are served by Meals on Wheels each year."

"This is part of a long narrative of Trump’s disregard for veterans and military families," Fischer said of the blocking.

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"Trump only wants to surround himself with Yes-men," said Fischer, citing a video of Monday's cabinet meeting in which the attendees praised Trump in an effusive way that was mocked by some.

It's not the first time the president has blocked his critics on social media. Also on Tuesday, he blocked noted science fiction and horror novelist Stephen King, Center for American Progress fellow Rebecca Buckwalter-Poza, and March for Truth organizer Jordan Uhl.

The president appeared to go on a blocking spree throughout the day, also blocking former Guantanamo Bay guard Brandon Neely. In a tweet about being blocked by Trump Tuesday, Neely suggested the president could be "blocking all veterans."

Looks like he is blocking all veterans. Blocked me as well pic.twitter.com/m4HqyXIAsV — Brandon Neely (@BrandonTXNeely) June 13, 2017

So many people have been blocked from reading or responding to the president's tweets that the hashtag #BlockedByTrump began to take off on Tuesday. Because Trump has blocked so many users, there are several other accounts — like @subtrump and @unfollowtrump — that retweet all of his posts on the platform.

Trump's blocking has caused concern in legal circles, where some have raised questions about whether it could be illegal for a sitting U.S. President to intentionally hide his statements from members of the public.

Related: Trump's Self-Inflicted Wounds Keep Coming, One Tweet at a Time

On June 6, attorneys from the Knight First Amendment Institute at Columbia University sent a letter to Trump asking him to unblock users. The letter says that an elected president's Twitter account is a "designated public forum" — similar to a school board or city council meeting — and blocking Americans from seeing and responding to it based on their viewpoints is a violation of the First Amendment.

That same day, White House Press Secretary Sean Spicer told reporters that Trump's tweets are "considered official statements by the president of the United States."

The Knight First Amendment Institute is currently soliciting submissions from other people who have been blocked by the president.

Fischer said that he wasn't very surprised about VoteVets.org getting the president's block treatment.

"If the campaign taught us anything," said Fischer, "It's that the days of disbelief and shock are over."