I think it’s prudent to assume that improved technology will eventually make it possible for anybody to read the encrypted documents that you send via email today. Similarly, you should probably assume that any photos in which you appear that are posted on the Web, even without captions, will eventually be searchable. (Being searchable by name is merely a matter of linking your image to one captioned photo.) Depending on the sophistication of the search algorithms and the quality of the images, this should apply to crowd photos, other people’s snapshots where you appear in the background, etc.
Search algorithms are Google’s strong point, and the Company already has a very effective text-based “Image Search” system. Improvements in that system seem certain, and I’m sure will bring widespread benefits that offset at least some of the costs. However, it’s increasingly clear that privacy as it existed before 1995 is a thing of the past.
From a business POV we are still in early days. Google reminds me of Microsoft in the early ’90s, except that I think Google has greater potential. The next few years should be interesting in many ways.