Quite some time ago I formulated what I call "the First Law of the Internet". I believe it provides a better formulation than a simply saying "do no harm".
The reason that I believe that it is better is that the "do no harm" approach is that there is almost aways some grounds for someone somewhere to claim that he/she is harmed.
My formulation makes it clear that anyone who claims harm must be asserting a harm to the public and places the burden of proving his/her case onto the person asserting the harm.
Here it is:
The First Law of the Internet
Every person shall be free to use the Internet in any way that is privately beneficial without being publicly detrimental.
The burden of demonstrating public detriment shall be on those who wish to prevent the private use.
The public detriment must be of
such degree and extent as to justify the suppression of the private activity.