The reaction to the whole affair demonstrates pretty clearly that most people expect their internet traffic to be private, regardless of how easy it is to intercept, a detail to which they are oblivious. As others have pointed out, some degree of voluntary respect for privacy and property is necessary in a civil society.
On the other hand, there are limits on how far we are expected to go to respect those rights. For example, if you have no signs, fences, or intrinsic indicators of ownership on your land, it may not be reasonable to expect people not to trespass. If you leave an old chair on the sidewalk, you probably can't call it theft when someone takes it away. If you are having a loud conversation in a public place, you should expect others to listen in, and so on.
There is presently very little consensus on which expectations are reasonable with regard to info tech. There is obviously a huge rift between the technoratti and the layperson, but neither of those subsets has a stable consensus either. The domain is changing too fast for even experts to establish lasting standards.
In the particular matter of wireless data, I would hope, ultimately, that nobody will expect data they are broadcasting through the air, for 100 meters in every direction to be private, especially when that supposed privacy could be breached as an unintended side effect of various benign activities, and when the capability to encrypt the data is readily available to everyone.