I see this argument all the time, pointing out anti-corporate people's hypocrisy, and it seems like a real solid zinger, but it's actually a logical fallacy. It's a form of tu quoque, which is a form of ad hominem.
To illustrate why this is faulty logic, let's take two heroin addicts. Heroin addict A says to heroin addict B, "Hey man, you should probably stop doing so much heroin. It's bad for your health and is ruining your relationship with your family." Is heroin addict A a hypocrite? Absolutely. He is telling somebody that heroin is bad for them while he himself is a heroin addict! But what does this mean for his argument itself? Nothing at all. The truth of heroin's health effects in no way is reliant on what the person making the argument does with their life.
So, people that hate corporations are using iPads and cellphones and shopping in chain stores. Does that alter the truth (or lack of truth since I'm not actually making that argument) to their argument? Absolutely not. Now, are corporations evil? Maybe, maybe not. That isn't what I'm arguing. I am arguing that a reply pointing out hypocrisy is not a good counter-argument to the argument of the hypocrite.
