Avoid these Panasonic/Lumix models.

Panasonic have been downloading a sneaky patch to their cameras' firmware that will stop the camera working unless you use Panasonic's own branded batteries.

http://panasonic.jp/support/global [...] ttery.html

Best advice is to avoid downloading any firmware updates for the models listed above and, perhaps, to avoid buying any model of Panasonic Lumix camera in case the policy is later applied to further models.

If you have been affected by downloading the patch unintentionally, in some jurisdictions you may, conceivably, have grounds for legal action against Panasonic or its parent company Matsushita, for example under restriction of trade laws, breach of data protection law or damaging your property by altering your camera's performance subsequent to purchase.