Anyone who can watch you will watch you. In technology, that is one of the big lessons of 2013. The National Security Agency and who knows who else have been tracking this or hacking that. China has been breaking into our computers. Google has been sifting through our home networks. Facebook has been tinkering with its privacy settings. No wonder outfits like Snapchat have exploded onto the scene. They seem to go against the grain, holding out the promise that all those selfies, texts and emails will simply vanish.