Yes, free VPNs are allowed to sell your data. While they’ll rarely make it plain and obvious that they’re doing so, it will be addressed in their terms and conditions. Of course, you accept these terms and conditions when signing up for the free VPN service. Not all free VPN providers sell your data but may do. For this reason we recommend you read the smallprint before signing up. In fact, we recommend you just avoid using a free VPN altogether.