On the contrary, it's unreasonable to make a broad claim based on one or two examples. When people say "I keep seeing people do this," it's based on a memory of repeatedly seeing similar things, not any one specific example they have in mind. Similarly, I noticed today that a lot of people around here have silver cars, but I couldn't name for you any specific silver car I saw on my commute today.
Well sure. But at the same time, it would be setting a bit too high a standard for me to expect people to do a scientific study for every silly little comment they leave on HN, don't you think? If someone claims that something happens "all the time", don't you think it's reasonable to expect that person to have observed it at least once or twice recently? Or at least be able to provide a reason why they don't have one or two examples?
My point is that there's a difference between passively observing something multiple times and remembering precise secondary details about the instances when you observed the thing. I remember seeing lots of silver cars quite well, but I don't remember any specific details about the cars — and remembering the make and model of a car is a lot easier than remembering the URL of a Hacker News posting.
At any rate, I just don't see why it would be useful for him to have specific examples in mind. What is the point in asking for that?
It's important to verify your intuitions, and it doesn't have to be a grand science experiment or a research project. If your intuition is that there are a lot of silver cars, a good place to start would be remembering the last time you saw silver cars. Or you could pay attention to the silver cars you see and take notes about the details that you feel are relevant. If it's worth it, then you can do a more in-depth analysis.
Now that said, there's not really much wrong with making broad assertions about the number of silver cars you're seeing without a more in-depth analysis. Chances are, nobody will care if you're wrong. There is something wrong with making a broad claim about things other people are doing without at least a little bit of evidence to support what you're doing. Just giving a list of search results and expecting others to find their own evidence isn't the best way to go about doing that.
