Caution Internet rip-off!

When I just wanted to load the game on my PC, I had an ABO contract must agree with a strange company called "Steam". I fear that it could invest it this organization, ripping off money.
In addition, I had to realize that this game you can play well only with Internet connection, which in my opinion sounds very suspicious.
My previous match (Quantum of Solace) worked, however, quite normal.
I wonder why I have a internet connection and a suspicious company need to play ???
To avoid scammers to run here in the case, I have returned to the game immediately, it ohen to load.