The terror threat is growing exponentially on the homefront.

A report on Wednesday from the Federal Bureau of Investigations revealed that there are currently more than 850 open investigations into domestic terrorism across the country.

And that number is continuing to grow, according to top counterterrorism officials.

The FBI, Justice Department and Homeland Security officials testified before a congressional committee on hate and violence here in America.

They also warned about a slippery slope, saying you can’t prosecute someone based only on an ideology or an online manifesto – they have to actually demonstrate intent to harm or harass.

And thanks to the internet, domestic terrorists, much like foreign terrorists, are able to quickly radicalize without needing to meet up in person.

“There’s a lot of hate out there on the internet,” said Mike McGarrity, the FBI’s top counterterrorism official. “Violent extremists around the world have access to our local communities to target and recruit and spread their messages of hate on a global scale, as we saw in the recent attack in Christchurch, New Zealand” he said.

It was a reference the mosque attacks that killed 51 people.

Late last month, a gunman killed a woman and wounded an 8-year-old girl, her uncle and a rabbi at a Southern California synagogue.

According to McGarrity, there were six deadly domestic terrorism attacks in 2018 and five in 2017.

Out of all of the open FBI investigations, half of them are anti-government cases.  About 40% pertain to race or religion.

According to McGarrity, preventing terrorism in the U.S. is the bureau’s top priority.

“We don’t differentiate between a domestic terrorism attack we’re trying to stop or an international terrorism attack. It’s a terrorism attack we’re looking to stop,” he said.

But here’s the thing – there’s actually no statute on domestic terrorism.  The Justice Department has to rely on other statutes to prosecute what they call “ideologically motivated violence” by individuals who no international ties.

The problem is that it makes it difficult to track how often extremists driven by religious, racial or anti-government bias commit violence in America.  It also makes it harder to develop a universally accepted definition of domestic terror.

Committee Chairman Bennie Thompson said he wants more information and is concerned by a lack of public information on the issue.

He went after the FBI for stopping a monthly briefing to the committee on threats to the nation.  That briefing included updates on domestic and international terrorist organizations and counterintelligence threats.

He said we have a responsibility to better understand the growing domestic terror threat.

“To all of the victims, survivors and communities who have felt like the terror you suffered was ignored or minimized, know that it ends today,” said the Mississippi Democrat.

Brian Murphy is Homeland Security’s deputy undersecretary for intelligence and analysis.  He said department officials are working on intelligence more than ever before.  As far as how they’re getting better?  He says they’ve created a round-the-clock open source collection team to track and share potentially threatening information.

“We continue to refine that and get better at that,” he said.