Haha I don't look like the vault boy. It is technically copyrighted, but using it for fun on a social media platform shouldn't be a problem. Loads of people use the vault boy as their avatar. What's more, there is a lot of Fallout fan art which uses 'copyrighted' images. Take a look on deviantart and you'll find loads. I don't think it's a huge problem as long as you don't use it for your legally registered business.

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