Things to point out
Google Streetview is repeatable; someone you know happening to see you becomes word of mouth but if it's on Streetview it can be called up time and again.
Streetview can allow the cross-referencing of address with the image being displayed whereas a chance appearance in a photograph may be tricky to pinpoint in an area the observer is unfamiliar with.
Streetview is available to the public, so not only can the anonymous spooks or powers that be see it, but everyone else can as well, thus opening a far wider window of viewers.
Now the question is do you trust Google to decide what is or is not appropriate to photograph or what is or is not an unethical activity? Does someone in the closet or secretly having a smoke or whatever have the right to choose to not be recorded by this system in light of these three differences over traditional media? If they have that right then consequently it should not be used as one cannot successfully selectively censor such a large system.