From The Huffington Post:
Do you own a pre-2012 Amazon Kindle e-reader?
If so, you have until Tuesday, Mar. 22 to install a critical update. Failure to activate it by then will mean the device loses connectivity, rendering your Kindle almost useless.
If you don’t install the update, you’ll still be able to read the books you’ve downloaded to the gadget. But you won’t be able to download Kindle books from the Cloud, access the Kindle Store or use various other services on the device, according to Amazon.
Link to the rest at The Huffington Post and thanks to Randall for the tip.
Here’s a link to the Kindle Update Information. You should update your device by tomorrow.