The first part of the first question gets answered in the court room, if it isn't answered by a settlement first.
The second part of the first question has different answers, depending on who you're asking. The dominant position currently is that only anticompetitive things that harm consumers should be illegal. (If you only consume free services like, say, Gmail, by definition you cannot be harmed under this theory.) Less radical theories also hold that the marketplace should be competitive, and there are other theories.
Making patents illegal would be pretty weird, given that a patent is a monopoly that wouldn't exist without government intervention.
The second part of the first question has different answers, depending on who you're asking. The dominant position currently is that only anticompetitive things that harm consumers should be illegal. (If you only consume free services like, say, Gmail, by definition you cannot be harmed under this theory.) Less radical theories also hold that the marketplace should be competitive, and there are other theories.
Making patents illegal would be pretty weird, given that a patent is a monopoly that wouldn't exist without government intervention.