Social network icons have become part of the popular culture and their recognition on the level of a pictogram has created specific symbolic language which provides a seance of belonging and safety. Converting that symbolic system into a font was just a matter of time.
Though their origin is mostly typographic, those icons are enhanced with other elements of a visual identity like colors, illustrations and stylistic decorations. Reducing them to monochromatic pictogram in some cases is bringing a harsh decision to make but mostly, the level of recognition stays preserved.
Alex Peattie has made a transparent collection of monochromatic pictograms, named JustVector Social Icons), which Sergio Diaz aka. Martian Wabbit converted into a font. Both of them are distributed under Free Art License (http://artlibre.org/licence/lal/en).
Unfortunately, because of the different origin of logotypes and distinguished number of characters that font is not working on the typographic level. I decided to correct those anomalies by setting the same x-height to all characters and rescaling other elements into the same frame. You can download the final result and use it freely under the previously mentioned license.