There's been a lot of furore over this, a rather politically incorrect article written for TIME by Dr. Scott Haig (full story here on Psychcentral). The tone of the article is more suited to a doctor's lounge and definitely not a national magazine, but if you take away the personal irritation he felt at the patient, his point is not invalid. You do see more and more patients coming in armed with incorrect knowledge they got off a forum, and doctors are spending more and more time trying to explain away the mistruths on the web. As a psychiatrist, I've had patients stop antipsychotics because they read a scary story about side effects on the web (even though I'd explained to them earlier the miniscule chance of the same side effects and the risk-benefit ratio). And they never called me until their family realized they were flushing the pills and seeing things again.
That being said, my usual question to patients with an established diagnosis is, 'What do you understand about your illness?' In most cases, they know very little. Some of it is the fault of healthcare providers for not providing adequate information, making multiple diagnoses and then changing them every few months, and being too chicken to say 'We don't know what you have.' Sometimes it is simply due to the poor insight associated with chronic or severe mental illness. I'm delighted if a patient has googled his diagnosis, his medications, side effects, Anything related to his condition. No matter if its wrong, at least I know that here is a dedicated person who is committed to getting better, wants to know whats going on, definitely has some insight, and will push me to expand my skills.
So hey, give me a googler anyday.