It's for this reason I have only ever used assets that were released as commercially usable and no credit required. I can never keep track of the THOUSANDS of assets I've used... so I just made sure I would never have a problem digging into my downloaded archives of what came from where... but if you're not selling, you'll never get in trouble, simple as that. It's the tiniest crime that at worst will have an artist getting annoyed. (I've gotten annoyed twice, by people who obviously traced my artwork and obviously the commissioner never told them I was the original artist of the map they copied) So, you might be asked to give credit or edit that asset out if someone is annoyed, but if you're not selling your art, just showing it, all that happens is you have achieved an internet nemesis. You won't get sued. You could if you sold your art though.

Go ahead and share, we'd love to see what you've made.