"What's wrong with the oil companies making profits? "

First, there is nothing wrong with making a reasonable profit. Even making a really good profit is ok, if that profit was made legitimately and in a fair and competitive environment.

Unfortunately, that is not the case with the oil companies in the US.

There are tremendous barriers for competition to enter. Thus, the oil industry is a closed market. Once a market is closed, the rules of free market pricing break down. Once a market is closed, you give those in the monopoly the ability to set whatever prices they want as they have little concern for a sleeker, less greedy company to undercut them. Of course the importance of the particular product limits pricing, particularly if the product is a luxury and not a necessity. In the case of oil, it is a necessity. Thus, once a product reaches the level of necessity and it is a monopoly then it needs to be regulated in order to keep people from being pillaged.

Also, the price of oil is not determined by OPEC, it is determined by the energy traders, of course those with the most influence being the oil companies themselves. They definately manipulate the prices. Is what they are doing illegal? I don't know, but they certainly push the limits of legality.