What happened The stock market rallied on Monday, and the Nasdaq is up nearly 5% in late morning trading. Yet one of the hottest "coronavirus stocks" -- companies investors have so far considered immune to the ill effects of the virus -- is falling. As of 11:40 a.m. EDT, Zoom Video Communications (NASDAQ: ZM) shares are down 7.8%. Why? Image source: Getty Images. So what For the answer, we turn to the pages of today's The Washington Post, which reports "some school districts around the country have started to ban the use of Zoom for online learning from home." These bans come in response to an FBI warning about the phenomenon of "Zoom-bombing" -- malefactors hijacking Zoom teleconferences and inserting themselves into the meetings. Days after the FBI issued its warning, reports the Post, "the New York City Department of Education, which runs the largest school district in the country, said teachers should no longer use Zoom" and should instead use Microsoft's (NASDAQ: MSFT) Teams software for online collaboration and videoconferencing. Clark County Public Schools in Nevada is also disabling Zoom access among its students and teachers. The Alpine School District in Utah is "reassessing" its use of Zoom, the Edmonds School District in Washington state is tightening security measures within Zoom, and "some elementary-school teachers" in Los Angeles are discontinuing use of Zoom on their own initiative, also reports the Post. Now what Is all this a tempest in a teapot, a concern that can be easily erased as teachers new to Zoom get better acquainted with how to use their security settings to keep intruders out of their online classrooms? Perhaps. In the meantime, though, the negative PR surrounding Zoom stock is growing, and Zoom stock is trading at a staggering 1,300 times trailing earnings -- and even 53 times trailing revenue. Even for often richly valued tech stocks, those numbers suggest that these shares were priced for perfection. The fact that Zoom has been found to be even slightly short of perfect therefore implies that the shares deserve to fall. Find out why Zoom Video Communications is one of the 10 best stocks to buy now Motley Fool co-founders Tom and David Gardner have spent more than a decade beating the market. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* Tom and David just revealed their ten top stock picks for investors to buy right now. Zoom Video Communications is on the list -- but there are nine others you may be overlooking. Click here to get access to the full list! *Stock Advisor returns as of March 18, 2020 Teresa Kersten, an employee of LinkedIn, a Microsoft subsidiary, is a member of The Motley Fool's board of directors. Rich Smith has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Microsoft and Zoom Video Communications and recommends the following options: long January 2021 $85 calls on Microsoft, short January 2021 $115 calls on Microsoft, and short May 2020 $120 calls on Zoom Video Communications. The Motley Fool has a disclosure policy.Source