yes! your OCs are extremely personal and important to you, so it makes sense that you would be protective of them, i’m the same way!

so, there’s one thing you’re gonna have to accept right now, and that’s that sometimes, it’s just going to happen no matter how much you don’t want it to. young artists that don’t know any better and adult artists who are just pieces of shit will try to go against your wishes and use your art/OCs in ways you’re not comfortable with. you can take comfort in the fact that they will never be as good as the original if they keep trying to steal from or copy you. that doesn’t mean you should be OK with it or not try to stop it, however.

my advice is take preventative measures: WATERMARK YOUR WORK, and make it very clear what you are and aren’t ok with in terms of how people use your art/OCs. make a plan of action on what to do when these things happen. 

approach the person calmly but firmly, let them know you’re not alright with what they’re doing and to please stop. if they don’t, you let them know there will be consequences. either blocking, reporting, or legal action if they’ve taken it that far. it’s important they know what will happen if they don’t respect your wishes.

in my experience, these things don’t happen that often, so you shouldn’t worry TOO MUCH about it, or let it stop you from posting your work online!

i post my art on instagram which is a hell site unmatched by tumblr or twitter combined. i’ve gotten more art and OC theft in my few months there than my years on other sites. i post a warning every time i upload a new drawing that i will stop posting on instagram if they continue to steal (etc). i can honestly say that it’s helped a lot!! i made it clear what i am and am not okay with, and what will happen if my boundaries aren’t respected.

hope that helps!!!!