Seems the days of surfing the Internet in the little black and white browser of the Kindle to your hearts content has come to an end.
Apparently, some users have experienced a bandwidth warning, alerted to a “50MB limit”. They were then informed that they would be allowed only 24 hours more of surfing and then access would be limited to Amazon.com, the Kindle Store and Wikipedia (unless you’re on wifi).
There always was a limit, apparently, just Kindle never enforced it until now. I suppose that is what you get when people start exploiting generosity.