Ok I'm sorry I think some of you are missing the point. I have no desire to base my fictional characters on real people. I was just using a reference of inspiration based on someone or incident I knew of in real life and would fit an easy start of for creating a fictional bad demeanor. Didn't Steven King once write one of his novels based off a real incident or person he knew in real life which was turned into a monster? Didn't Lovecraft write novels based off his nightmare which he wrote into the Cthulhu myths and even James Cameron had created some of his movies like Terminator which was based off a guy that wanted to go after him or something like that? Can't life experiences sometimes be a good influence into writing your plots and help you come up with newer ideas?
I'm just going to put this out there:
I base all my characters on real people.
But not the petty details like looks or names or anything like that. I base my characters on real personalities I encounter because that is more interesting since how people are in real life is way beyond anything I could come up with on my own. It also helps me a lot when I'm stuck, particularly in dialogue.
As far as getting into any trouble about this. Well, whether I intend to or not, I find that as I write my story and my characters encounter different events, they morph away from the original people I based them on. In other words, now that I'm at the end, my characters barely resemble their inspirations at all.
But the core personality traits are there, and I think that's okay.
Do I worry about the people who inspired my characters recognizing them? To be honest, no. After all, my characters and their inspirations really don't resemble each other in their physical features or in their names. Also how I think people are in my own head differs dramatically from what they're actually like. And besides, no matter how I come up with a character and personality, there will be someone out there who resembles that to a T and that's just life.
Now of course, if you're really worried about writing a character that's too similar to someone you know, you could always reach out to the person who inspired and ask them what they think. I've done that with most of the people I base my characters on and none of them have given me the stink eye for it. Most of them get a kick out of it.
As far as villains go, I think it's fine to base them on real life, so long as you're only using them as a starting point and develop the character further as you go along. (but PLEASE do not use their real names. You want to give yourself some plausible deniability here) I also think it's interesting to combine personality traits for villains, so that's another option. Rather than just relying one person as inspiration, you pull from several different people, layer it together and mix yourself a really nice Baddie Smoothie that doesn't resemble the pieces you started with at all.
Anyways, those are my two (more serious) thoughts on the subject and good luck!