Maybe someone (with a big following on Twitter, let's say) needs to start compiling a list of national government and EU websites that publish user generated content, for example petition sites. If the law goes through, people can go to those sites and post "unexpectedly copyright infringing" content, such as a paragraph from a book (perhaps a self-published one that consists of just seemingly contextless paragraphs).
(Inb4 the national laws end up including huge exemptions for site run by the government or political parties).
A more technical campaign would be reverse engineering the filtering algorithms (censorship machines) that sites end up forced to install, and finding a way of generating new copyrighted content that has the equivalent of a "hash collision" against already popular (or political) content hosted on websites using the filter.
