server:~# apt-get install telnetd
Reading Package Lists... Done
Building Dependency Tree... Done
telnetd is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
Need to get 0B/41.1kB of archives.
After unpacking 0B of additional disk space will be used.
Selecting previously deselected package telnetd.
(Reading database ... 47605 files and directories currently installed.)
Preparing to replace telnetd 0.17-29 (using .../telnetd_0.17-29_i386.deb) ...
Unpacking replacement telnetd ...
Setting up telnetd (0.17-29) ...

server:~# apt-get remove telnetd
Reading Package Lists... Done
Building Dependency Tree... Done
The following packages will be REMOVED:
  telnetd*
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
Need to get 0B of archives.
After unpacking 98.3kB disk space will be freed.
(Reading database ... 47617 files and directories currently installed.)
Removing telnetd ...
groupdel: cannot remove user's primary group.
dpkg: error processing telnetd (--purge):
 subprocess post-removal script returned error exit status 8
chown: cannot access `/usr/lib/telnetlogin': No such file or directory
dpkg: error while cleaning up:
 subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
 telnetd
E: Sub-process /usr/bin/dpkg returned an error code (1)