I recently had a need to stop and re-start f.lux (on Windows). I noticed that it was slow to start and suspected it was accessing the network. Since I had disabled automatic updates, that was strange.

Switched to process explorer and found f.lux connected to three different addresses out there on the wild internet.

Fishy, to say the least. You need permanent internet connections to do what you're ostensibly doing? Replaced it with open-source alternative "redshift".