That might be the case. In my case I got apt-get back by removing the google accounts package.

> Date: Mon, 5 Sep 2016 07:01:47 +0000
> From: <email address hidden>
> To: <email address hidden>
> Subject: [Bug 1617564] Re: package kaccounts-providers (not installed) failed to install/upgrade: trying to overwrite '/etc/signon-ui/webkit-options.d/www.facebook.com.conf', which is also in package account-plugin-facebook 0.12+16.04.20160126-0ubuntu1
> 
> Could kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb be
> the problem?
> 
> Just tried to uninstall kde-config-telepathy-accounts using ~# apt-get purge and got 
> "is not installed, so not removed" 
> 
> one DEB keeps showing up in failed processes, that is:
> 
> kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb
> 
> in
> 
> /var/cache/apt/archives/
> 
> Noted this Having done this round of commands, each recommended by the previous process. kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb showed up 6 times.
>   
> ~# apt-get purge kde-config-telepathy-accounts
> ~# apt-get -f install
> ~# apt-get autoremove
> The package system is broken
> Check if you are using third party repositories. If so disable them, since they are a common source of problems.
> Unchecked all non Canonical repositories and updated out of date packages successfully.
> Furthermore run the following command in a Terminal: apt-get install -f
> ~# apt-get install -f
> ~# apt-get autoremove
> ~# apt-get autoremove -f
> 
> -- 
> You received this bug notification because you are subscribed to a
> duplicate bug report (1617978).
> https://bugs.launchpad.net/bugs/1617564
> 
> Title:
>   package kaccounts-providers (not installed) failed to install/upgrade:
>   trying to overwrite '/etc/signon-ui/webkit-
>   options.d/www.facebook.com.conf', which is also in package account-
>   plugin-facebook 0.12+16.04.20160126-0ubuntu1
> 
> Status in One Hundred Papercuts:
>   Confirmed
> Status in kaccounts-providers package in Ubuntu:
>   Confirmed
> 
> Bug description:
>   showing this error when installing kde environment in ubuntu 16.04. it
>   say kaccounts  niot installed. so i think it may cause some security
>   issue
> 
>   ProblemType: Package
>   DistroRelease: Ubuntu 16.04
>   Package: kaccounts-providers (not installed)
>   ProcVersionSignature: Ubuntu 4.4.0-34.53-generic 4.4.15
>   Uname: Linux 4.4.0-34-generic x86_64
>   NonfreeKernelModules: wl
>   ApportVersion: 2.20.1-0ubuntu2.1
>   Architecture: amd64
>   Date: Sat Aug 27 18:11:18 2016
>   DuplicateSignature:
>    package:kaccounts-providers:(not installed)
>    Unpacking kde-config-telepathy-accounts (4:15.12.3-0ubuntu1) ...
>    dpkg: error processing archive /var/cache/apt/archives/kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb (--unpack):
>     trying to overwrite '/usr/share/accounts/services/google-im.service', which is also in package account-plugin-google 0.12+16.04.20160126-0ubuntu1
>   ErrorMessage: trying to overwrite '/etc/signon-ui/webkit-options.d/www.facebook.com.conf', which is also in package account-plugin-facebook 0.12+16.04.20160126-0ubuntu1
>   InstallationDate: Installed on 2016-08-25 (1 days ago)
>   InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
>   RelatedPackageVersions:
>    dpkg 1.18.4ubuntu1.1
>    apt  1.2.12~ubuntu16.04.1
>   SourcePackage: kaccounts-providers
>   Title: package kaccounts-providers (not installed) failed to install/upgrade: trying to overwrite '/etc/signon-ui/webkit-options.d/www.facebook.com.conf', which is also in package account-plugin-facebook 0.12+16.04.20160126-0ubuntu1
>   UpgradeStatus: No upgrade log present (probably fresh install)
> 
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