Some call it water, some call it H 2 O. The molecular makeup of this life-sustaining liquid has many arrangements and monikers, but they all amount to the same substance that pours from our faucets and quenches our thirst.

However, late last month Long Beach resident Tammy Hall learned that when posted on a street sign, two atoms of hydrogen and one atom of oxygen can amount to several hours of police detention, after a passerby reported a threat warning of an imminent “dihydrogen monoxide” attack.

The day was August 26 and Hall had just wrapped up one of the annual water fights she hosts in her Bluff Heights neighborhood. There were hundreds of water balloons, super soakers and kiddie pool refill stations that fueled the ranks of the nearly 20 participants. Signs were posted all around her home at the corner of Temple and Third, advising that a water war pitting adults versus children was scheduled for noon.

One sign that Hall hastily authored with a red Sharpie marker read, “Sometime around midday, Temple & 3rd is declared a war zone. We will not care if you are unarmed. ☺ If you enter the area you may be exposed to large amounts of dihydrogen monoxide. It would be better if you came prepared. Safety third!!”

When the two Long Beach Police Department (LBPD) vehicles pulled up to her home, the sign was the furthest thing from Hall’s mind.

“We had anticipated that of course sometimes they shut these things down, so we ran over,” Hall said of the lemonade stand that her two daughters were operating. “That’s when they informed me that there had been some sort of FBI terror alert that had just come out that morning around the same time that my sign was reported.”

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Hall was detained for over two and half hours while the officers communicated over their radios, letting Hall know that while they were aware they were responding to a water fight “it was out of the LBPD’s hands.”

Marlene Arrona, a spokesperson for the department, confirmed officers were dispatched to Hall’s neighborhood to investigate suspicious activity. She said a passerby who found a posted sign “alarming and a threat to the community” notified the LBPD and a threat investigation was conducted as part of the department’s investigation. Despite Hall’s comments about the FBI, Arrona maintained the LBPD is the lead agency in the investigation.

Hall was cited for posting illegal signage under the Long Beach Municipal Code and later released, despite an ongoing investigation.

Hall, who has a scheduled court date at the end of the month regarding her citation, said the situation was both eye-opening and dumbfounding. In an age where most people have smartphones, she was of the opinion that it was ridiculous to think a person would get reported for a threatening sign that also contained a smiley face.

“If you see something that causes you some alarm you’d look into what you’re alarmed about, I would think,” Hall said. “Never in my wildest dreams did I think people would actually be scared. I thought actually it would be a good laugh.”

Hall is not the only one to run afoul of hydrophobia.

In 2004, a proposed law that would’ve banned the use of foam cups in Aliso Viejo was placed on its city council agenda because the cups contained dihydrogen monoxide. Staff reports characterized the compound as a threat to health and safety before it was eventually pulled from the agenda because of “bad research.”

A Canadian lawmaker tried to ban Dihydrogen Monoxide from all federal buildings in the country in 2010 because of its prevalence in toxic compounds and it being lethal if inhaled. The politician, Andrew Scheer, went on to become Canada’s Speaker of the House of Commons.

Most recently, two Florida disc jockeys (DJs) were suspended from the air in 2013 after an April Fool’s Day joke where they said on air that Dihydrogen Monoxide was coming out of Floridians’ taps and was not safe for consumption. The hoax caused concern among residents, resulting in numerous calls to water suppliers.

The DHMO “movement” has several pages dedicated to it on social media, where an endless stream of memes tying Dihydrogen Monoxide to negative consequences abound. One page on Facebook titled “Dihydrogen Monoxide Awareness” has a link to a meme generator and a store where DHMO water bottles and coffee mugs can be purchased. One dollar from every item sold is donated to water.org, a group dedicated to providing safe drinking water for all.

Hall said that she’s now jokingly sent those very memes from friends and neighbors who have caught wind of her legal troubles because of her DHMO warning sign. It’s those very friends that she said she’ll need to reach out to if she ends up having a fine levied against her that is more than negligible.

With summer over, and the need to cool off tapering down with the temperatures, Hall has no plans for a water fight in the near future. But, fine or no fine, she said the water wars will continue next summer…just with less threatening signage.

“My kids always look forward to one really big water fight where we just call out all our friends; they put on war paint and everything for it,” Hall said. “That won’t stop. I just won’t put out warning signs with chemical compounds on it. I’m just glad we didn’t list the side effects of dihydrogen monoxide—that would’ve made it worse.”