"There's no way they would stoop that low."
I'm not sure you are familiar with the history of the police state. Just when you think they won't go below a certain bar, then do. Why do you think, when performing any other manner of illegal and unconstitutional things, they wouldn't add one more to the list, especially when there seems to be no repercussions?
I'm also reminded of occupy wall street, in which is was found out after the fact that:
"Banks sat down with FBI officials to pool information about OWS protesters harvested by private security; plans to crush Occupy events, planned for a month down the road, were made by the FBI – and offered to the representatives of the same organizations that the protests would target; and even threats of the assassination of OWS leaders by sniper fire..." - Revealed: how the FBI coordinated the crackdown on Occupy - Naomi Wolf
Much later we even found out the CIA had some involvement, and that's an organization which is not supposed to operate domestically! So, I think you are being naive in putting the abuse of zero-day cell exploits past them, especially when it might not even be the police forces themselves, any number of three-letters could just be seeing this as a good realistic training exercise to test out their latest toys.