Twitter slaps limits on sales of its pricey stock

While Facebook prepares to go public, Silicon Valley's other buzzy social startup, Twitter, is doing everything in its power to stay private. In pursing that goal, it has slapped its shareholders with an unusual restriction: No one who holds stock can sell more than 20% of their shares.

Source: http://rss.cnn.com/~r/rss/money_technology/~3/zOiQ9i005bU/index.htm

MICROCHIP TECHNOLOGY METHODE ELECTRONICS MENTOR GRAPHICS IMS HEALTH IMATION