The chapter analyses the normative power of digital platforms, highlighting how terms and conditions of service constitute instruments of unilateral imposition of contractual rules. The platforms, in a dominant position, define constraints to which users adhere without the possibility of negotiation. A comparative survey of the most recurrent clauses adopted by operators such as Amazon, Facebook, TikTok, Booking.com , Airbnb, YouTube and LinkedIn is proposed. The analysis shows the risks of contractual imbalances and vexatious clauses, prompting reflections on regulatory safeguards and remedies.