The two tech giants have been told by the European Commission that they are still not doing enough, despite warnings made nearly a year ago.
"As social media networks are used as advertising and commercial platforms, they must fully respect consumer rules," said the European commissioner for consumers Vera Jourova.
"I am pleased that the enforcement of EU rules to protect consumers by national authorities is bearing fruit, as some companies are now making their platforms safer for consumers; however, it is unacceptable that this is still not complete and it is taking so much time."
The commission did however welcome efforts made by Google to comply with the rules, such as ensuring it provided a deadline for fulfilling requests to remove illegal content online.
The three Silicon Valley companies were told last year they must make several changes to their terms and conditions. That includes clearer explanations of the circumstances under which content can be removed as well as appeal procedures, something neither Facebook or Twitter have yet done.
All three companies have changed referencing the EU jurisdiction rather than California laws so that EU residents are not prevented from bringing any actions in the EU courts.