You can't address "the source of the problem" without a benevolent eye toward human vulnerabilities. We do volunteer information frivolously "just because some site asks for it" -- in return for a minimal value. That does not make us stupid. That is human nature. Human weakness. The average human does not, and cannot, look ahead that far.
When businesses capitalize on human nature, human weakness, that's not OK. It's unethical. Our society is afraid to use the statistics of human behavior to say, "business cannot capitalize on the human weaknesses in the manner of a, b, c." Somehow our human weaknesses are ignored, belittled, treated as an unmentionable embarrassment. We cannot say, "50% of humans do "x" therefore you may not merchandise based on "x". Somehow it makes our species feel too stupid, to be seen as a species with limitations to our collective reasoning powers.
We all (acording to our behavior) long for a white-haired person to trust, to give us a permanent cure to bad breath, etc. Human "weaknesses" (in other words, instincts honed by millenia of natural selection) are exploited, in our lifetimes to an unprecedented degree of sophistication, to sell products. But nobody feels comfortable saying it's wrong. Instead of saying, "All humans trust old folks in a position of prominence, do not market that way!" we say, "People are stupid to trust TV ads showing old folks in a position of prominence." This is completely illogical to blame humans for their instincts!!!
Dudes! our instincts to trust, or not trust, are completely natural and sane. INSANE is using adverts to place "old folks in a position of prominence" as maketing drones. It's a complete misuse and overthrow of otherwise-sensible and otherwise-useful instincts.