Comment 5 for bug 505278

Upstream says that this is security vulnerability.
I agree.
An important one too!

User can have action (like shortcut, screensaver, timeout, whatever) that does ssh-key -D,
and he expect that his SSH keys are now secure... while they are still accessible!

Upstream also says its most likely a problem with seahorse or other ssh agent; Although when I killed all my agents (seahorse*, ssh-agent) the same problem seemed to exist still - read comments in upstream bug report.