[abustamam]

> A marketer's definition of anonymized is worthless. It's a fantasy they want everyone else to believe in.

I'm using your definition.

> Does it map to a single, identifiable person or something close enough that the distinction is meaningless?

Also

> If it can be "de-anonymized" then it was never anonymous to begin with.

Well sure, that's the point I was trying to make in my rhetorical question above. Individual pieces of data may be "anonymous" but put together with other anonymous data that can be traced to a single source and suddenly you can figure out quite easily who this person is. The data itself is still technically anonymous but it can be pieced together.