I can see what he's getting at, though.
Do you remember when it became possible to do reverse lookups on phone numbers, using computers? Until that time, one could only search oneway, from the name (and possibly address) and find a person's phone number. But when PCs got sufficiently powerful, there appeared on the market CDs which were effectively giant telephone directories of the entire country. Suddenly (given the right kit) one could find a person's address given no more than their phone number. The easy availability of reverse lookup doubtless has had a social effect.
Again, no difference in principle (before this, one could, theoretically have done reverse searches anyway). But in practice, it made all the difference. Put it this way, the principle may be black-and-white. But how things pan out in practice is always in shades of grey. For practical purposes, that shading matters.