BOGOTÁ, Colombia—"Just landed in Columbia. On my way to the hotel," Paris Hilton tweeted last year as her plane touched down in Bogotá for the opening of one of her handbag shops.

But before she left the airport, there were scores of replies like this: "PARIS, IT'S COLOMBIA, NOT COLUMBIA!!!!" The celebrity great-granddaughter of hotel magnate Conrad Hilton soon corrected her tweet.

Big outfits including Virgin Mobile, P.F. Chang's and Lufthansa—and performers including Justin Bieber and Ozzy Osbourne—have all in the past year committed this boo-boo, which really annoys Colombians. They have spelled the country's name with a "u" the way you would spell Columbia the university, or the sportswear company, or the U.S. capital, Washington, District of Columbia.

Now, tens of thousands of Colombians are fighting back by linking up with a movement called "It's Colombia, NOT Columbia."

From Facebook to Twitter to Instagram, as soon as the spelling mistake is found in social media—and it is found a lot—no time is wasted in shaming big companies, celebrities and sports stars into fixing their error, using the hashtag #itscolombianotcolumbia.