The internet and social media have fundamentally changed the nature of electoral campaigns. Voters have unprecedent access to information about elections and electoral contestants, and they are able to express their political views to a large online audience. Furthermore, voters can easily interact with candidates and become actively involved in online campaigns. Candidates and political parties are using internet platforms to present their agenda to the electorate and to mobilise political support at low cost. On a large scale, they can even deliver individualised “target” messages in order to attract voters (see CoE study DGI (2017)11). At the same time, however, the use of online media poses new challenges to uphold the principles of fair and clean electoral campaigns.