How is on USA companies cooperating with each others (Microsoft and Apple on 90s vs. Sun is the example in my head) is illegal, while the government cooperating

How is on USA companies cooperating with each others (Microsoft and Apple on 90s vs. Sun is the example in my head) is illegal, while the government cooperating with a company is fine? USA doing kind of like China, trying to make it the easier it is for companies to prophet from the people even if it's something supposed to be owned by the people... =