In this case, the "exception" is not an exception to the rule. It's an exception of the object to which the rule applies.

Let's say we have a rule that is said to be valid for all mammals. To prove the rule ("make it more likely" to be strict) we should check it for exceptional mammals like the whale (a huge mammal that lives in the water). When the rule applies for these cases, the rule is more likely to be true cause people that make rules tend to overlook exceptional/extreme cases.

In Brazil every kid knows how to lie the date of birth in order to create an Orkut account.

Of course you do. And that's why it gets upvoted.

But you are not enriched by comforting, unverifiable group-think.