You follow the brand guidelines as best you can as an icon supplier then it's most likely on the site/app using them to follow the guidelines too to avoid issue

You follow the brand guidelines as best you can as an icon supplier then it's most likely on the site/app using them to follow the guidelines too to avoid issue https://en.facebookbrand.com/guidelines/brand https://en.facebookbrand.com/guidelines/brand https://en.instagram-brand.com/guidelines/general https://en.instagram-brand.com/guidelines/general https://github.com/logos https://github.com/logos