When you walk in the street, do you choose whether I see your or not? Why shouldn't consent be necessary in that case, but should be in others?
EDIT: Who sets the limit between what is implicitly private and public? Let's say I made the decision to add thermal vision to my left eye, and happen to see what you do inside your house. Am I hurting your privacy?
Obviously. But it's only because historically people couldn't listen to it without serious effort and if they did that it usually had malicious intent.
If your phonecall is as easy and neutral to observe as your face or height when you show up on the street you can no longer expect it to remain private.
Same way you coldn't expect conversation between two distant parties to be private before phone was invented an it could only be performed by shouting.
Taking a dump wasn't private act before toiled was invented and probably it won't again be when cameras will be as small as dust particles self powered wireless and everywhere.
Privacy of actions is noT some philosophical absolute. It's just function of what technology is available to how many people.
Personal communication has thought to be private since ancient times. Emissaries were expected to deliver notes to the recipient without reading or tinkering with them in any way. And it goes a far way as communication goes, since mail (the paper, clay, stone, wax or whatever thing) has been assumed to be private since those times.
Also, I don't think my face or height are adequate analogies when playing against my wages, food preferences and trade secrets. All these details can easily give unfair advantage to "other parties" whereas my face or height couldn't help much except deciding I'm likely no good at basketball
