Earlier quoted context omitted.
Facebook is not a data monopoly, unless you take "data monopoly" to mean "has a set of a data that no one else does", in which case everyone is a data monopoly.
Nobody else has a comparable dataset on a comparable scale. Microsoft wasn't the only company supplying operating systems in the 1990s either.
Think about how much data Amazon has about all the suppliers and products they've sold over the last twenty years. Should they be forced to hand it over to anyone who wants it just because of the fact that its size and exclusivity makes it very valuable?
What about the governments databases on everything under the sun? Should all of that be public?
Maybe the answer to the above questions is yes, I don't know, but I don't think it's axiomatic.