I find these claims extremely dubious. Everything they claim the Pi is needed for can be accomplished without the equipment and postage costs with a purely software solution; The hardware allows them to monitor all traffic and avoid antivirus/firewalls. Moreover, I doubt it is difficult to find mass-market Facebook accounts for much less than $15/month - it is far more likely that, given the hardware allows them unfettered access to all network traffic, it is designed to report back as much data as possible, ideally including plaintext passwords and banking information.