https://finance.yahoo.com/news/better-congress-zuckerberg-gates-155325918.html

Broadly speaking though, you could say that Microsoft and Facebook were called before Congress for the same reason. Lawmakers considered them to be too big and needing oversight. Both Microsoft and Facebook, of course, are West Coast behemoths, far from the purview and reach of Washington, D.C. and its bureaucrats.

More similarities: Both Gates and Zuckerberg went to Harvard and dropped out, and of course both are consummate, iconic billionaires idolized and celebrated in movies and on magazine covers, and also lambasted as awkward, clueless over-empowered uber-nerds.