: How many corporations have committed fraud, violated laws, flagrantly abused the environment, etc. Who is to stop them?
Given that you consider these laws to be the product of corporations in the first place why then do you imagine they would make a law in order to break it?
You exaggerate the extent to which corporations can buy or bribe laws. Its not as one sided as many socialists appear to think - any criticism should be about the principle behind a given law being broken, rather than about the relative size or influence of particular corporations.
If, for instance, you decide that the free movement of people and material is a good principle to stand by then you must rail against all laws restricting this - whether they be laws which purport to protect 'big business' from competition or 3rd world import tariffs and ceilings which purport to pretect fledgling and vulnerable populations. If you think about laws in this way then you realise that you can't have your cake and eat it too - and more over you realise that many interest groups are behind 'bad laws' not just the easy targets of 'big business'
That is the essence of my argument - that just blaming all 'big business' for everything thats wrong with the world is just another wrong itself.
: Doesn't the internal logic of capitalism guarantee the generation of these monsters of profit whose control of governments is just "part of doing business"?
No it doesnt - no part of 'private property' requires by logic or otherwise that it become as you describe - that it has in many cases is well worth exploring and criticising, but just saying 'its inevitable' is to suggest some universal law of nature is in operation.