The European Commission, in cooperation with the UK’s Competition and Markets Authority, opened a formal antitrust investigation Friday into whether Facebook has breached EU competition law.

According to Executive Vice President Margrethe Vestager, who is responsible for EU competition policy, over seven million firms use Facebook for advertisements. The investigation comes as a result of the social media platform’s alleged use of competitors’ advertising data to get ahead in markets where it is active. The investigation also aims to examine whether there are ties between the classified online ads service “Facebook Marketplace” and the platform itself.

EU and British regulators will assess whether Facebook uses its position to get ahead of its competitors via exploitation of commercially valuable data allegedly provided to it through “Facebook Marketplace.” One way in which this may be done is by receiving precise information on user preferences from competitors’ activities and then using this information to adapt itself to reach consumers.

In light of this investigation, Vestager said that, “[I]n today’s digital economy, data should not be used in ways that distort competition.”

If the allegations are proven, there may be potential breaches of Articles 101 and 102 of the Treaty on the Functioning of the European Union (TFEU). These articles address competition rules on anticompetitive agreements between companies and the abuse of a dominant position.