A member of the Facebook group said, “If you get a clear shot, fire for effect!” The Secret Service said it is aware of the post and is conducting the appropriate follow up.

An open carry advocate in Texas said he would bring his "rifle and hand out literature at SXSW Friday. I just found out Obama is going to SXSW Friday. This may get interesting," according to messages on a private Facebook page obtained by BuzzFeed News.

Everytown for Gun Safety

One commenter, Kriss Elliott, replied to the message, "if you get a clear shot, please fire for effect!"

Everytown for Gun Safety

Grisham didn't immediately respond to a request for comment. The screenshots were provided by Everytown for Gun Safety, which advocates for gun control measures.

A Secret Service spokesperson told BuzzFeed News in a statement that it they are conducting a follow up.

The Secret Service has the authority to preclude firearms from places, including those located in open carry states.

"Individuals determined to be carrying firearms will not be allowed past a predetermined outer perimeter checkpoint, regardless of whether they possess a ticket to the event," according to the Secret Service statement.

Open Carry Texas is "dedicated to the safe and legal carry of firearms openly in the state of Texas," according to its website. The purpose of the organization is to educate Texans about their rights and encourage elected officials to pass less restrictive open carry legislation, according to its website.

Open carry became legal in Texas in January of this year.

Grisham told KEYETV that members of the organization will be outside the Austin Convention Center Friday to engage with younger people.

"We want to educate them and show them that an armed society and be a polite society," he told KEYETV. "There's noting to be afraid of just because I have a pistol on me at all times.

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