Twin directories of backports.org:

[DIR]  ftp://ftp.uni-frankfurt.de/pub/Mirrors3/backports.org/
[DIR]  ftp://ftp.skynet.be/mirror1/backports.org/
[DIR]  ftp://ftp.mgts.by/pub/backports.org/
[DIR]  ftp://128.237.157.9/archive.debian.org/backports.org/
[DIR]  ftp://ftp.tu-ilmenau.de/Mirrors/ftp.de.debian.org/backports.org/
[DIR]  ftp://ftp.debian.de/backports.org/
[DIR]  ftp://77.88.19.68/backports.org/
[DIR]  ftp://ftp.ibr.cs.tu-bs.de/mirror/backports.org/
[DIR]  ftp://ftp.uni-augsburg.de/mirrors/debian/backports.org/
[DIR]  ftp://ftp.uni-kl.de/pub/linux/backports.org/
[DIR]  ftp://ftp.estpak.ee/pub/backports.org/
[DIR]  ftp://ftp.at.debian.org/backports.org/
[DIR]  ftp://ftp.uk.debian.org/backports.org/
[DIR]  ftp://ftp.uvsq.fr/pub/debian/backports.org/
[DIR]  ftp://128.237.157.10/backports.org/
[DIR]  ftp://ftp.debian.de/archive/backports.org/
[DIR]  ftp://ftp.inf.tu-dresden.de/os/linux/dists/debian/backports.org/
[DIR]  ftp://ftp.inf.tu-dresden.de/os/linux/dists/debian/archive/backports.org/
[DIR]  ftp://ftp.hands.com/backports.org/
[DIR]  ftp://wt t0_Series004_z005_ch01.tif/.sda1/backports.org/
[DIR]  ftp://128.237.157.10/pub/backports.org/
[DIR]  ftp://131.246.120.85/pub/linux/backports.org/
[DIR]  ftp://77.88.19.74/backports.org/
[DIR]  ftp://93.158.155.193/backports.org/
[DIR]  ftp://128.237.157.9/pub/backports.org/
[DIR]  ftp://77.88.19.73/backports.org/
[DIR]  ftp://128.237.157.9/backports.org/
[DIR]  ftp://128.237.157.9/pub/archive.debian.org/backports.org/
[DIR]  ftp://195.238.1.7/mirror1/backports.org/
[DIR]  ftp://ftp.las.ic.unicamp.br/pub/debian.d/backports.org/
[DIR]  ftp://ftp.europeonline.net/backports.org/
[DIR]  ftp://ftp.3logic.net/backports.org/
[DIR]  ftp://ftp.ru.kernel.org/backports.org/