On one side, many endorsed the link tax as an instrument to protect the work of publishers and a way to ensure that users may access their online contents. On the other side, however, many express fear regarding the fact that small publishers will be significantly penalized (indeed, search engines will not be interested in displaying the contents of small publishers, as long as they need to pay for such service).
Source: DSM And Link-Tax: Protection For Copyright Or For Leading Publishers? – Intellectual Property – UK