This is a true story that is really happening, as The Hollywood Reporter notes that Burger King's Russia division has filed a complaint with the Federal Anti-Monopoly Service asking that Andy Muschietti's IT be banned for the reason that Pennywise looks too much like Ronald McDonald. They say that because of the similarities, IT serves as free advertising for McDonald's, and that's unfair.
Clearly, whoever is filing this suit in Russia hasn't seen IT, because if they think that people coming out of the Stephen King adaptation want to run right over and EAT anything being served by Pennywise, they're nuts. Also, I know that Ronald McDonald looks different in different countries, and that international versions of the fast-food clown COULD bear some similarity to Pennywise. But there's no way audiences are confusing this