Behavioral Retargeting? good or bad?

Professor Kagan mentioned in last week's class, as I'm sure as he will in many future classes, the impending benefits of behavioral targeting. So far, we have addressed it in the context of SEO, as in the first piece of information (the launch point) retargeters can gather about a non-converted user. I'm sure in the next few weeks we'll delve deeper into how paid search and display media are the vehicles through which advertisers can retarget their non-converted users, but I want to discuss my slight personal aversion to the practice in general. Behavioral retargeting, though it may prove to be monetarily efficient, is in my opinion just another example of information gatherers' refusal to respect online privacy. Isn't it a bit invasive? My computer presenting custom information to me based on my previous searches? To some degree it feels unfair. How do YOU know what I want to see today, simply based one what I saw yesterday? However, this perspective is rebutted by the data. On the one hand, if this were the case, then the results wouldn't be so stellar....the high conversion rates are evidence of the fact that users do find this method useful I suppose. On the other side, I could argue that these conversions are just a measure of short-term gains, and in fact may harm long-term relationships between retailers and their consumers. My point, simply, is that I can't be the only one irritated by this, and we should not throw caution to the wind in the name of a quick sale. It would be interesting to gather long-term data on the effects of behavioral retargeting before we push it as the next frontier.