Previously any client with good bandwidth, no restrictions due to firewall or network address translation (NAT), and adequate processing power could become a supernode. This placed an extra burden on those who connected to the Internet without NAT, as Skype used their computers and Internet connections as third parties for UDP hole punching (to directly connect two clients both behind NAT) or to completely relay other users' calls. In 2012, Microsoft altered the design of the network, and brought all supernodes under their control as hosted servers in data centres. Microsoft at the time defended the move, saying they "believe this approach has immediate performance, scalability and availability benefits for the hundreds of millions of users that make up the Skype community." At the time there was some concern regarding the privacy implications of the change, which appear to have been proven true with the revelation of the PRISM surveillance program in June 2013.