Alice Van Ness, who was hired to teach hour-long yoga sessions at Facebook's Menlo Park campus, says she tells students before class to turn off their cellphones.
But a female employee pulled out her cellphone in the middle of a Monday session and began texting.
The San Jose Mercury News says Van Ness didn't say anything, but she gave the student what she calls a look of disapproval.
The student later complained and Van Ness was fired by Plus One Health Management.
The termination letter says Van Ness "made a spectacle" of the student.
Information from: San Jose (Calif.) Mercury News, http://www.mercurynews.com