Act sensibly on the net and you'll be fine for the most part.
That sounds suspiciously like the "only criminals have something to hide" defense, thinly veiled with a qualifier that defeats any merit your point might otherwise have.
Yes, we get it, people who experience serious retribution likely did something to provoke it. Thank you, oh oracle of ancient triteness, er, wisdom.
Yes, the prior poster could have expressed their position more effectively, but you haven't actually countered it. What exactly is your response, in the event that someone's information is dredged up and used to destroy them? It seems self-evident that even innocuous statements can be twisted into damaging weapons for the person with any reputation worth destroying.
These 'what if' scenarios are so statistically insignificant, particularly if you follow the sensible part I mentioned, that it's basically a barrier to being able to use technically in a useful and fun manner.
Please don't confuse hypothetical situations with statistics. If you're going to claim that they bear any relation, please cite studies or some very convincing proofs. As it stands, you're arguing that something that isn't a statistic has no statistical merit and is therefore moot, while insinuating that your wholly unqualified, unverified concept of sensible behavior - whatever that means - holds some degree of the same.
Now then. In the entirely possible case that someone is badly affected by the use of such collected data, what protects them?