Free speech is an incredibly low bar to set yourself. If 'not breaking the law' is the only barrier between your brain and your mouth then you are an unkind, mean-spirited, thoughtless, a-hole.
The law isn't a set of rules for how we should behave, it's a last resort when someone is bahving SO badly they need to be physically stopped!
There are posters at my kid's school that say "Before you speak, THINK" and that acronym means you shouldn't say something unless it's "True, Helpful, Inspiring, Necessary, and Kind". I really wish more adults would consider this before they open their mouths.
Just because you CAN say something, and even if it's true ("you're really fat") doesn't mean you should.