Bismillahi Rahmanik Raheem, Assalamu Alaikum
This is something I have been thinking about for some years now, if User agreements found in software are legal in Islam, recently it was answered by one of the Faqih of ahl al Ghayb.
The User agreements people are forced to sign before using software are not legal in Islam because there is no agreement/contract on something after a sale, that is after you have already become the owner of it. If a company wants to legalize it they must place this agreement before the sale, before you have taken ownership all previous agreements are null and void because of this.
Shaykh Rami Al Rifai.
“O you who have believed, obey Allah and obey the Messenger and those in authority among you.” (4:59)