I am not a lawyer... but,
Modern tort law states.
Intrusion upon seclusion occurs when a perpetrator intentionally intrudes, physically, electronically, or otherwise, upon the private space, solitude, or seclusion of a person, or the private affairs or concerns of a person, by use of the perpetrator's physical senses or by electronic device or devices to oversee or overhear the person's private affairs, or by some other form of investigation, examination, or observation intrude upon a person's private matters if the intrusion would be highly offensive to a reasonable person.
Unless this does not apply to LEO...
In theory you could expand this ruling to include monitoring of a persons latptop as long as they where not at home, to view connections made but not the actual communication, perhaps extending to his communication. Or even extended to snooping any wireless communication that can be received in a public place, even using basic encryption that is known to be compromised ie wep etc. (read below)
The argument which is kinda valid, is that the information of placing a tracking device can be obtained by following the person, hence the argument that it tracked him into a non private place IE his garage, while in theory a violation of privacy is still info that could be obtained visually from public view.
To me this appears to be spirit vs letter of the law issue. The letter of the law does make this type of tracking legal, but is that really the Spirit of the Law... I can see lots of loopholes extending from this ruling.