A little-appreciated downside of the technology revolution is that, mainly without thinking about it, we have given up 'locational privacy.'

Serving up ads based on behavioral targeting can itself be an invasion of privacy, especially when the information used is personal.

DMs are a lot like email - and should have the same privacy protections as a mailed letter.

For technology companies, information about what people do online is extremely valuable - it can be used to sell targeted advertising or sold to data clearinghouses.

The remarkable thing about 'Avatar' is the degree to which the technology is integral to the story. It is important to show Pandora and its Na'Vi natives in 3-D because 'Avatar' is fundamentally about the moral necessity of seeing other beings fully.

The public has a right to know what kind of monitoring the government is doing, and there should be a public discussion of the appropriate trade-offs between law enforcement and privacy rights.