GAK

[Douglas Barnes]

One good (non-cypherpunk) argument against GAK is that it
concentrates a very large quantity of valuable keys in a few
places, where they become an extremely attractive target for
government or corporate espionage.

You could compare this to the function served by banks, but
banks tend to notice fairly quickly when money is missing.
Compromising keys doesn't involve removing anything, or throw
the books out of balance; they just get copied. The compromise
is only revealed if they are used clumsily.

Note that a few million keys would fit very easily on even a
low-end DAT tape (easily hidden in a pack of cigarettes).