If it’s illegal for the government to snoop directly, it’s illegal for the government to pay someone to snoop. This is elementary and should be clear even to a journalist.
Problem is, the government is already doing it.
“it’s illegal for the government to pay someone to snoop”
The businesses do the snooping whether the government pays or not. So it’s not “contract work” they are doing on behalf of the government. It’s not really “snooping” either, since the users consent to having the data collected.
The government just comes along and buys that collected data like any other business can buy it, except the government is not buying it for business purposes.
It probably should be illegal, but it isn’t. Pretty big loophole, and it’s probably the reason the government will never actually crack down on the social media sites.