If google or 'anyone with a camera' established a persistent surveillance operation outside your house that is not legal, that is stalking. http://www.nij.gov/topics/crime/stalking/Pages/welcome.aspx
Which is funny to me they try this anyway, how hard is it to get a warrant these days?
Pretty difficult if you don't actually have a specific target
(IANAL) The majority opinion in Kyllo seems to have established that external surveillance featuring commercial, off-the-shelf devices did not require a warrant. Anything which features non-commercially available technology does.
Notably, Scalia dissented in his majority as arguing that even commercial availability (which changes as future tech popularizes) was a dangerous precedent to set and the line should be further in favor of home privacy. The dissent argued that the external nature of the surveillance made a warrant unnecessary.