Brand icons may be subject to trademark and brand guidelines of their
respective owners. Always check before deploying other companies’ branding.

Brand Icons:
fa-adn
fa-android
fa-apple
fa-bitbucket
fa-bitbucket-square
fa-bitcoin (alias)
fa-btc
fa-css3
fa-dribbble
fa-dropbox
fa-facebook
fa-facebook-square
fa-flickr
fa-foursquare
fa-github
fa-github-alt
fa-github-square
fa-gittip
fa-google-plus
fa-google-plus-square
fa-html5
fa-instagram
fa-linkedin
fa-linkedin-square
fa-linux
fa-maxcdn
fa-pagelines
fa-pinterest
fa-pinterest-square
fa-renren
fa-skype
fa-stack-exchange
fa-stack-overflow
fa-trello
fa-tumblr
fa-tumblr-square
fa-twitter
fa-twitter-square
fa-vimeo-square
fa-vk
fa-weibo
fa-windows
fa-xing
fa-xing-square
fa-youtube
fa-youtube-play
fa-youtube-square

Brand Guidelines (incomplete list):
Android: http://developer.android.com/distribute/googleplay/promote/brand.html
Apple: http://www.apple.com/legal/intellectual-property/guidelinesfor3rdparties.html
Dribble: http://dribbble.com/branding
Dropbox: https://www.dropbox.com/branding
Facebook: https://www.facebookbrand.com/
Foursquare: https://foursquare.com/legal/trademark https://foursquare.com/about/logos
GitHub: https://github.com/logos
Gittip: https://www.gittip.com/about/terms/
Google Plus: https://developers.google.com/+/branding-guidelines
HTML5: http://www.w3.org/html/logo/
Instagram: http://help.instagram.com/304689166306603/
LinkedIn: http://developer.linkedin.com/documents/branding-guidelines
Pinterest: http://business.pinterest.com/brand-guidelines/
Skype: http://www.skype.com/en/legal/brand-guidelines/
Stack Exchange, Stack Overflow: http://stackexchange.com/legal/trademark-guidance
Tumblr: http://www.tumblr.com/docs/en/trademark_guidelines
Twitter: https://about.twitter.com/press/brand-assets
Vimeo: http://vimeo.com/about/brand_guidelines
Windows: http://www.microsoft.com/en-us/legal/intellectualproperty/Trademarks/Usage/Windows.aspx
Xing: https://dev.xing.com/docs/policies
YouTube: http://www.youtube.com/yt/brand/