A little over a year ago I created this post, calling out anyone using Web CEO, SEOmoz’s Rank Checker, or SpyFu as being dishonest. My intent wasn’t to make anyone feel guilty or really call anyone out, my intent was that hopefully someone could convince me I was wrong, and that violating Google’s terms of service is, in fact, not dishonest. Some people have submitted interesting arguments, but so far the best one is that while any website can put up a terms of service agreement, this does not actually mean anyone using the website is dishonest if they violate it, it just means they open themselves up to whatever consequences Google cares to muster, the primary consequence being that Google might interfere with your activity. In other words, the purpose of the TOS is not so much to modify behavior of users, but to give Google the right to do whatever it sees fit if users do things they don’t like.
You might compare it to an “No Trespassing – Armed Response” sign on a fence bordering private property. Is the sign saying that if you trespass you’re a criminal? No, but it’s saying if you do trespass, the owner reserves the right to shoot at you with a gun, and you’ve been duly warned. Can Google’s TOS be taken in a similar light? That is, I can send automatic queries with a clear conscience, I just need to be aware that Google reserves the right to combat my activities in any way they see fit, and I’ve been duly warned of that fact? Or, when I visit their site, am I formally entering into a binding contract and giving my word to follow their TOS, any violation of which makes me a liar?

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I’ve been wondering the same thing. What I’d really like to know is if I have some automated script that innocently grabs some useful info every once in a while – nothing malicious at all – then what is the worst they can do to me? If all they can do is interfere, then fine, I’ll go ahead and try, but if the TOS gives them the right to take any kind of legal action, I’ll think again. Does anyone know to what extend they can take action?