Various police departments received calls throughout the day that there was an active shooter on the campuses.
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The claims turned out to be unfounded.
The six schools located across the region in the East Bay, the South Bay, the Peninsula and in San Francisco.
Schools that were impacted include McClymonds High School in Oakland, Irvington High School in Fremont, Lincoln High School in San Jose, George Washington High School in San Francisco, Woodside High School and South San Francisco High School.
"Someone calls in and they create a fake emergency. And that emergency is supposed to be this extraordinary chain of events that causes a tremendous amount of panic," said Ray Kelly of the Alameda County Sheriff's Office.
It's a tactic known as swatting.
"At first I didn't know what was going on until I saw a lot of cops with their guns out, and that's when I started to feel a felt a little bit more safe," said Christopher Govea, a student at South San Francisco High School.
But swatting isn't just happening here in the Bay Area. This is a trend nationwide, and many mental health experts say it can cause some serious problems.
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"It's incredibly traumatic. And a lot of us have PTSD from the other school shootings that have happened and the other threats that have happened," said Dr. Andrea Zorbas.
Zorbas is a clinical psychologist who says the impacts of swatting can be felt by teachers, parents and students, as well as by the wider community.
"It's something that doesn't just sort of go away when we know that the threat is over. It's something that sticks with us for a little while," she said.
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And while parents tell us they're thankful that no one was injured due to Wednesday's false alarm, they worry where swatting might take us next.
"I think that the worry is even stronger with these hoax calls because you fear the next time that something really is happening, that perhaps they won't respond with such efficiency like they did today," said Amanda Parker.
There was a large police presence at some of the schools, where parents showed up to make sure their kids were OK.
Grace Hernandez says she left work immediately after receiving a message from her daughter at Woodside High School.
"It was around 10, she told me that she was scared because she wasn't sure what was going on, and all she knew was to hide," Hernandez recalled. "When I answered her text and she didn't reply back immediately, then after a few minutes back she said that they were under a shooting threat."
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Like many parents on Wednesday, Hernandez was relieved to find out this was not a real threat.
Police say this is what's known as swatting, where someone makes a prank call to get a large response from law enforcement.
Alameda Co. Sheriff's Lieutenant Ray Kelly says this is a new phenomenon. He explained the motive behind the threat, which he says is usually done anonymously through a digital platform.
"It's to create havoc and chaos and anarchy. That's what it's designed to do. The perpetrators are usually young people," Kelly says.
Kelly says they believe the calls Wednesday are related to a series of calls from last month and that one person may be behind this.
There are several law enforcement agencies working on this investigation.