Alexis Ohanian has left Reddit's board in a 'long overdue' move. Here's how he launched Reddit into a $3 billion behemoth and became an outspoken activist in the tech world.

· Alexis Ohanian, who cofounded Reddit in 2005, has been called the "Mayor of the Internet."
· He and cofounder Steve Huffman built the company over 16 months, then sold it to Condé Nast in 2006 for somewhere between $10 and $20 million. Today, the company is worth $3 billion. 
· Since then, Ohanian has become a venture...