If you don’t want to swear, don’t swear. Mildly censoring a swear word to “f*ck” doesn’t accomplish anything. Everyone who reads it knows exactly what it says. And if you go far enough to make it unrecognizable, like “!@#*”, now you’re just pretending to swear, but for what purpose? Couldn’t you accomplish your goals by rephrasing to avoid a swear word entirely? (Assuming your goal is to avoid swear words, of course. If the goal is to sound like a cartoon character, consider taking up a funny catch phrase.)

Edit: Oh, and this is missing the original point entirely: the original post said “fkn”. That is their freedom of speech. Someone else decided to censor it before sharing. That is not covered under their freedom of speech (well, technically it is, but it’s also a clear case of censorship.) If the original post didn’t contain any censorable words, that is completely up to the author. But if you share a post and felt the need to inject your personal belief that “fkn” is a no-no word? Nobody asked.