Bug#820423: snapshot.debian.org: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.

[Vincent Lefevre <vincent@vinc17.net>]

Package: snapshot.debian.org
Severity: important

After modifying /etc/apt/sources.list as explained on
http://snapshot.debian.org/ and doing

  apt-get -o Acquire::Check-Valid-Until=false update

I get among various messages:

N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.

which is completely unacceptable.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.4.0-1-amd64 (SMP w/12 CPU cores)
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)