Dark clouds heavy with rain are gathering over Sand Hill Road. Lightning strikes closer and closer to the penthouse conference rooms of major San Francisco law firms. Senior partners are padlocking doors, handing out candy and blankets, doing everything within their power to keep people in the building as the storm breaks.

What’s the threat, you ask? It’s the burst of movement of capable lawyers to in-house positions, lured by the stock options and opportunities for growth at Silicon Valley’s next billiondollarsurething.com.