Google Street View

No it is not an invasion of privacy because all pictures were taken within public domain. Pictures of such nature can not be considered as an invasion of privacy and be found all over the web.
Some of them are fun, some are educational, and some are just nasty (because the people who take these pictures look for smut - which is easy to find in any city!)

I don't really see how it's useful, it's a little fun because it's fun to spy on the neighbors and check out if you are in there (my apartment window is showing). However, I think that on a whole it's not a good thing, it's a serious invasion to privacy, as well as an alarming sign for a future where non is safe from a praying eyes.