IR Magazine has been looking at shareholder activism in Europe and quotes Manifest:

A different style of activism?
Historically, there have been obstacles to waging a successful activist campaign in much of Europe. Many markets are opaque, the proxy voting system has been leaky with votes often lost, and some countries still block any shares to be voted for several days prior to the AGM, putting a damper on shareholder participation. What’s more, in some countries, controlling shareholders enjoy additional voting rights, making it harder for other investors’ positions to gain support.

http://insideinvestorrelations.com/articles/18299/american-style-activism-takes-hold-across-pond/