Do you know what Pando Media Booster really is?

For those who keep Skype on, that program is doing the same thing.

http://www.rescomp.berkeley.edu/infocards/?topic=skype

 Spoiler

Skype is a free video/audio chat program for all operating systems. It lets you make calls to anyone and anywhere either for free if they also have the Skype client or for a small fee to phones. Many students have found it useful to stay in touch with home and friends. But there is a hidden side to the Skype interface that is causing a surge in your bandwidth consumption.

Some of you are familiar with P2P networks such as KaZaa and Limewire; Skype functions on a similar concept in that everyone that is part of the Skype network can be a client or a server. However, there are some users that use Skype while behind a firewall, which would normally prevent Skype from functioning properly. To get around this, users that are not behind a firewall that blocks Skype's connections become an enormous hub in which others connect to. You can think of it as... Friend A is on one side of a large wall and Friend B is on the other side, but they want to talk. So what happens is, a total stranger sitting on top of the wall listens to Friend A, and then yells down to Friend B the message, complete with pictures and vice versa. This continues until Friend A and Friend B finish their conversation. This way, Friend A and B can circumvent the wall that would normally prevent them from communicating.

So either go into options and disable it or quit Skype while playing games.