E.U. officials on Friday ordered Google, Twitter and Facebook to end scams on their platforms or face “enforcement action.”

“Social media companies must remove any fraud and scams appearing on their websites that could mislead consumers, once they become aware of such practices,” E.U. officials ordered.

Officials said E.U. consumer authorities and organizations have received a rising number of complaints from of victims of scams through social media sites.

Read: Email Security: Apple, Microsoft, Amazon, File Amicus Brief Over Google Case

Practices affecting consumers reported to the E.U. include scams involving payments from consumers, subscription traps (customers signing up for a free trial without being given clear information), counterfeit products and fake promotions.

E.U. officials also said consumers have been been subject to certain terms of services that do not comply with European consumer rules. The E.U. also said social media platforms should not deny consumers the right to take a case to court in their home country.

“It is not acceptable that EU consumers can only call on a court in California to resolve a dispute,” said EU Commissioner Věra Jourová in a statement Friday. “Nor can we accept that users are deprived of their right to withdraw from an on-line purchase. Social media companies also need to take more responsibility in addressing scams and fraud happening on their platforms.”

E.U. officials wrote a letter to Facebook, Google and Twitter telling the companies to look into both matters. On Thursday, E.U. consumer authorities and the European Commission met with the tech firms and discussed the companies’ possible solutions. The companies have one month to come up with solutions to comply with E.U. consumer law, officials said, adding if the proposals “are not satisfactory, consumer authorities could ultimately resort to enforcement action.”

Read: UK And YouTube: Government Pulls Ads After Learning They Were Featured Next To Extremist Videos

European officials have spoken against tech companies, including Facebook and Twitter numerous times. The E.U. has criticized the social media platforms for failing to decrease fake news and online hate speech on its sites.

Earlier this year, the E.U. also proposed rules that would limit how firms like Facebook and Google track users to deliver targeted ads, in an effort to help users protect their privacy online and provide more transparency from companies. The EU expects the proposal to be adopted by May 2018.