I think that the risks of doing this kind of get played-up a little bit. However, I always question why people want to post pictures of anything other than relatively rare guns.
You say that you just bought a new Glock 19? We're gun guys and gals, and we like to hear about stuff like that; but why do you need to show anybody a picture of it - we all know what one looks like, and yours is gonna be no different than anyone else's. You say you have a whole locker full of guns? OK, cool. But why do you feel the need to show them off? I just don't get the motivation. Besides, showing off a locker full of guns might just be of interest to agencies that, of course, strictly abide by the Bill of Rights and "do not illegally monitor the activities of law abiding citizens." (I don't think that concern is over-played in the least).
Now, tell us that you just acquired a NIB Japanese Nambu pistol? That is worth showing off! I'd sure want to see it. That's akin to the Holy Grail to gun enthusiasts, and I'm pretty sure we'd all want to see it.