At least until its version 1.157.4-1, `live-initramfs` has a [bug](http://lists.debian.org/debian-live/2009/09/msg00125.html)that makes it use any cleartext swap partition found on local hard disks.
It is recommended to securely erase, using a program such as `shred`, any cleartext Linux swap partition present on computers having been used with affected amnesia systems.