(CNN)The banners have been hung from highway overpasses and rooftops in several states across the country.
They're not discreet. And their creators -- usually white supremacist groups who proudly put their name and logo on the banners -- are not mincing words or using euphemisms, according to the Anti-Defamation League.
"WHITE FAMILIES MATTER." "FOR RACE AND NATION." "'DIVERSITY' IS A CODE WORD FOR GENOCIDE." "UNjew HUMANITY."
These are just some of the anti-immigration, racist or anti-Semitic statements displayed on the banners, and the underlying message is clear: If you're nonwhite and were not born in America, these groups don't want you here.
The banners have appeared more frequently in the past year, according to a report released Thursday by the Anti-Defamation League's Center on Extremism. It has counted at least 72 highly visible and disturbing messages deployed by mostly white supremacist groups since May 2017, a figure that "marks an unprecedented trend," the group said in a blog post labeled "New White Supremacist Tactic: Banners of Hate."
"We do not have a banner count for 2016 because it was not a common form of activism that year," says Carla Hill, an investigative researcher for the Center on Extremism. "While we have seen white supremacists post banners in the past, we have never seen banners used to this degree or this widespread."
Another reason the banners may be increasing in number, the report says, is because their messages of hate "can garner widespread attention with very little actual effort involved."
The banners were hung in 21 states and on average seven times a month, the ADL says.
One group, Identity Evropa, was responsible for 40% of all the banners, placing them in 13 states.
Identity Evropa displays one of its biggest drops at the top of the group's homepage, and posts about it on the group's blog.
Banner drops were most common in Oregon, California, Texas and Georgia, where the ADL says there are particularly active chapters of Identity Evropa and Patriot Front.
Many of the banners from Identity Evropa contain language like: "America First," or statements about securing borders or anti-immigration sentiment.
But the ADL warns that this organization is not like "mainstream" anti-immigration groups.
"These phrases are a sanitized version of the group's true aim: the preservation of 'white American identity' and the promulgation of the idea that America was founded by white people for white people, and was not intended to be a multiracial or multicultural society," the ADL says in its report.
The group placed an anti-Muslim banner across an overpass near Dearborn, Michigan -- a city with a large Muslim population -- that said: "Danger Sharia City Ahead," and featured images of women in burqas.
The ADL says white supremacist group Vanguard America has targeted women, as well as Muslim and Jewish people, in brazen ways, "Feminists Deserve the Rope" was displayed at a women's march in Providence, Rhode Island, and the group hung a banner at a Holocaust memorial in Lakewood, New Jersey, that said: "(((Heebs))) Will Not Divide Us."
The group Patriot Front capitalized on the debate over NFL players kneeling during the National Anthem in a banner it hung near the Dallas Cowboys football stadium that read: "Take a Knee Back in Africa."
Patriot Front has proudly posted images of its banners on its Twitter account. A representative from Vanguard America confirms the group was responsible for the banner drops the ADL mentions, saying, "These banners were dropped in the name of white nationalism."