Big companies do big mistakes:

Telecommunications company AT&T updated its terms of service for its DSL customers recently with an interesting addition: the company will now suspend the accounts of those who talk badly of it. The new line reads that service may be suspended if a customer’s comments “tends to damage the name or reputation of AT&T, or its parents, affiliates and subsidiaries.” Betanews.com

The reason for why big companies do big mistake is simple the fact that they are driven by fear. Fear is no good for creating future, only protecting history.
Thanks to Daniel Hjelmtorp for sending this link.