Frankly, many gun owners live in a state of constant paranoia of their own government, or of the UN boys in blue helmets, maybe the Chinese Army.
There are large US govt. computer departments, whose analysts who keep track of any comments made on gun websites about buying lots of ammo, and keep top-secret X-files on anybody with more than 200 rounds.
I don't have much either: only about 8,800 rds., not including .22:
1,100 .303, 1,900 x54R, 2,300 .223, 4,800 x39. Mini 30, SKS, MN 44 and a LE (hopefully) being shipped. This stuff was bought to avoid much higher costs in the future based on fuel/mineral prices last spring/summer.
Wish I had 15,000 rounds at '08 prices, as I'm not involved in illegal activities and this stuff is 100% legal.
The more popular calibers were all bought months before the election.