"The IAB strongly endorses the view of the Division Advisory Panel of the National Science Foundation Division of Network, Communications Research and Infrastructure which, in paraphrase, characterized as unethical and unacceptable any activity which purposely:

. . .

(e) compromises the privacy of users."

Compromising the privacy of internet users was unethical and unacceptable

Now, for companies that have popular websites but nothing to sell, it's a "business model"