A 20-year-old man from Tennessee was arrested on Wednesday for allegedly posting messages on an internet forum threatening to open fire in a Planned Parenthood facility in D.C. and threatening federal agents.

Jacob Cooper, who goes by the username “Jacco” on the website iFunny, responded to another user’s post on August 13, 2019 saying: “Make sure you tell them about how I plan to shoot up a planned parenthood facility in Washington D.C., on August 19th at 3pm,” according to court documents and a press release from the U.S. Attorney’s Office.

Later on August 13, Cooper allegedly posted again, saying “If you are a member of the FBI, CIA, whatever, and are on my profile I will trace your IP address and kill you if the opportunity arises. And I am dead serious about this. I’ll do it with a ricin bomb, or .308. Whatever it takes, the end result will be the same. I am serious about this. If I am personally contacted by any federal agents, I will do this. I will kill you. Again, I am serious. Sic semper tyrannis.”

The Latin phrase loosely translates to “death to tyrants.” John Wilkes Booth wrote in his diary that he shouted the phrase when he shot President Abraham Lincoln. Oklahoma City Bomber Timothy McVeigh wore a shirt with the phrase inscribed on it and a photograph of Lincoln’s face when he was arrested.

Cooper has been charged with making interstate threats and faces up to five years in prison, according to the USAO. He has a preliminary detention hearing on August 26.

He is one of at least four men arrested for threatening or vandalizing abortion clinics in the last month, two of whom were also posting to the meme-sharing site iFunny.

The threats are apparently part of a growing trend. There was a 34 percent spike in online harassment against abortion clinics in 2018 from the year before, according to data gathered by the National Abortion Federation.

“No one should ever face the threat of violence just for seeking health care,” Planned Parenthood of D.C. said in a statement about the charges against Cooper. “We are proud to provide a safe, welcoming environment for our employees and for our patients, so they can get the high-quality health care they need. We are strong, and our doors will stay open for everyone who needs our care. No matter what.”

This story has been updated with comment from Planned Parenthood.