\chapter{Related Work}
\label{ch:related-work}

This chapter gives a comprehensive overview about different projects trying to protect the users' personal data in online social networks. Hereby, six different approaches are presented. First, extensions are considered that make the use of established social networks more secure. Then, alternative social networks will be presented that have placed the protection of personal data at the center. Thereafter two next generation social networks will be considered, which take advantage of the blockchain technology and belong to the group of dApps. Finally, the ActivityPub protocol is presented, which maps the communication in decentralized platforms. The chapter concludes with a summary of the related work.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% For each project, write about
% - how is data stored
% - how is communication realized
% - how is data accessed (authorization)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Extensions for better privacy
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Privacy through Extensions}
\label{sec:extensions}
Existing connections to other people and already created content can bind users to platforms. This so-called lock-in effect prevents users from switching to another platform. In the following, Twitterize and FaceCloak are two approaches that make the use of Twitter and Facebook safer by protecting data.

\subsection{Twitterize}
\label{sec:twitterize}
\input{content/03-related-work/twitterize}

\subsection{FaceCloak}
\label{sec:facecloak}
\input{content/03-related-work/facecloak}

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% Privacy-protecting Social Networks
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Privacy-protecting Social Networks}
\label{sec:privacy-protecting-social-networks}

\subsection{diaspora*}
\label{sec:diaspora}
\input{content/03-related-work/diaspora}

\subsection{LifeSocial.KOM}
\label{sec:lifesocial}

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% dApps
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{dApps - The Next Generation Social Networks}

\subsection{Akasha}
\label{sec:akasha}
\input{content/03-related-work/akasha}

\subsection{Peepeth}
\label{sec:peepeth}
\input{content/03-related-work/peepeth}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Protocols
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Protocols}
\label{sec:protocols}

\subsection{ActivityPub}
\label{sec:activitypub}
\input{content/03-related-work/activitypub}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Summary
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{Summary}
\label{sec:related-work-summary}