A group of anti-transgender protestors showed up at a women’s soccer game between the Seattle Reign and the Orlando Pride at Seattle’s Lumen Field on Sunday following several local news reports that Pierce County Sheriff Keith Swank had been encouraging a demonstration.

But many attendees at the game only saw a “fortress” of trans Pride flags surrounding the protesters that largely blocked them from view, as one fan described it on social media. Some of the flags bore the slogan “Trans Rights Are Human Rights.” Per social media posts, the protesters wore apparel from the XX-XY brand, a women’s athletic gear brand that often contains lightly coded anti-trans messaging such as “Refuse to Pretend,” and that advertises its mission as restricting participation in women’s sports only to those with XX chromosomes.

Prior to the Sunday match, the Tacoma-based News Tribune reported that the sheriff for Pierce County, which contains Tacoma and the surrounding area, had allegedly been organizing an anti-trans demonstration through email.

Emails obtained by Defend Washington, a political action group opposed to a current Washington State ballot initiative seeking to ban trans girls from playing in girls’ school sports, showed that Swank allegedly planned to disrupt the match with anti-trans messaging. According to the leaked emails, he was looking for a group of people — up to about 90 — to purchase tickets in the same section of the field where Reign fans often wave Pride flags and other regalia.

An October 26 email from Swank, with the subject line “stand up for women and girls,” asked people to “Go into the stadium with your shirt covered, and at half time, put it on full display.”

Swank did not respond to a request from The News Tribune for its October 30 story about the planned demonstration. However, after the reporter attempted to contact Swank, he reportedlysent another email to the group of demonstrators claiming there was an “infiltrator” in the group who had leaked the protest to the media.

While the alleged emails between Swank and protesters were obtained by Defend Washington, Swank also posted about his plans on his official social media page. On October 24, Swank posted that he was looking for “a few (actually a lot) good men and women to join me. We will go to a sporting event where these radical leftists are (soccer or wnba), and we will wear xx-xyathletics.com.” He continued, “We will stand up for free speech. It will be a lot of fun. If you want to join just email me at: boysareboysandgirlsaregirls@gmail.com.”