I’ve been thinking along similar lines so it’s surprising to read this in an article. These huge corporations are the centre of so much economic activity that they’re bound to unwittingly participate in and benefit from at least some illegal (or at least, highly unethical) activity. The illegal and unethical aspects of their activities may be what gives them their competitive edge.

If a corporation breaks the law in any way, it needs to be shut down at least for some period of time (something like jail time for corporations). This would naturally prevent corporations from getting too big and would force them to be extra careful about what kinds of people they hire.