Wael Ghonim, Google's head of marketing for the Middle East and North Africa, hasn't been heard from since Friday at 6 p.m., his brother Hazem said. Hazem said the family is in touch with Google.
On Jan. 26 after Egypt clamped down on Twitter, Wael sent a tweet that was recirculated by colleagues, friends and strangers: "A government that is scared from Facebook and Twitter should govern a city in Farmville but not a country like Egypt," he said, referring to the Farmville Internet game by Zynga Game Network Inc.
On Friday, he tweeted: "Very worried as it seems that government is planning a war crime tomorrow against people. We are all ready to die."
A Google spokesman said: "We care deeply about the safety of our employees, but to protect their privacy, we don't comment on the individually."
In a releated news, on YouTube, thousands of videos of the protests have poured in, whether as unfiltered footage from the demonstrations themselves, or as news reports from our media partners around the globe.
Here's a playlist of vides that have come in: