Also, I thought I'd point out the value of forums: in all of these exchanges, it seems to take three people to get the "aha" moment, not just one or two.
Topic: some new superstrong carbon nanotube material is discovered.
A: So it seems like they're planning to use this stuff for armor. But what about weapons? It seems that anything strong enough to make good armor would also have value as a weapon.
B: That doesn't follow at all! They're completely different use-cases. For example, leather is known to make good armor, but you never see a leather sword!
C: Sure you do -- it's called a "whip" and we dig them up all the time!
Topic: Some dating site is blocked from emailing University of Texas students (at their school email) because of too much spam.
A: Well, their defense is that they're complying with the CAN-SPAM Act, in that they have an unsubscribe link, use their real name, etc., so UT can't just block them wholesale.
B: What? That doesn't matter; that's just the *minimum* requirement for sending such emails. Obviously, any domain owner can impose whatever extra restrictions they want!
C: Yeah, it's like saying, "I have a valid driver's license. I am the legal owner of this vehicle. I have paid the appropriate taxes and registered it. I hold the required liability insurance, and the vehicle is in good working order. I have complied with all applicable traffic laws and operated it in a safe manner. Therefore, I have the right to park on your lawn."
I actually use C's last example when explaining to people the difference between authentication (proving who you are) and authorization (what that identity is allowed to do).
