All those companies have very strict branding guidelines actually. I ran into this when designing a site for a corporate customer, we had to follow all the bran

All those companies have very strict branding guidelines actually. I ran into this when designing a site for a corporate customer, we had to follow all the branding/logo guidelines in the little social "connect to us" section. https://about.twitter.com/company/brand-assets https://about.twitter.com/company/brand-assets https://www.facebookbrand.com/dos-donts https://www.facebookbrand.com/dos-donts https://brand.linkedin.com/policies https://brand.linkedin.com/policies https://developers.google.com/+/branding-guidelines?hl=en https://developers.google.com/+/branding-guidelines?hl=en etc.