The questions is why? The first option suggested, to break them up in smaller companies will not work because in a network economy these companies will go on in sharing data. For instance, Facebook knows a lot about you, even when you are not a member. The second option is to hold back mergers. Though it would have been good that the EU had forbidden the merger of Facebook, Instagram of WhatsApp in 2014 the alternative of giving billions of penalties for Google, Facebook and the like does not work either. These companies are so rich that they simply can continue with their monopolistic activities.
In the last edition of The Network Society (2020) I offered two other options. The first is to create and update laws on the domains of data, content (freedom of expression and intellectual property), media diversity, privacy, labor conditions, consumer rights and tax legislation. The start of this is recently made by the European Commission with the Digital Service Act, The Digital Markets Act and the Data Governance Act.
These precursors of coming national laws, such as in Hungary have the right approach: it is to not control the platforms by direct government supervision but by self-regulation of the platforms themselves under the direction of clear regulations or laws.
These platforms should not decide themselves which hate speech etcetera will be blocked. This is undemocratic. To see whether they will do this according to the laws and regulation they have to be transparent and accountable for every action like filtering and blocking. This is my second option.
Another solution is to stimulate social media with another business model than the current advertisement led model. This might be a subscription model: a fee of, say 5 euro per month for a social medium that is privacy friendly, without advertisement and following the laws and regulation of a country. Today people find it normal to pay about 20 euros for a telephone subscription but do not want to pay for an alternative for Facebook, Instagram and the like.