Bunch of strawmen here.

> Is it wrong if I sit on my porch and record in a notebook the hair color of different people?

If you only count the number of redheads, you are in the clear. If you follow them around, find out where else they go, where they live, how many people live in their household, the household income, etc., you might violate some laws.

> Is it wrong if I observe that one of my coworkers has a Harley Davidson sticker on his laptop?

Of course not.