Complex sentence: The motive is often to prevent access to content which the computer's owner (s) or other authorities may consider objectionable; when imposed without the consent of the user, content control can be characterised a form of as internet censorship.
Split into simpler sentences: The motive is often to prevent access to content which the computer's owner (s) or other authorities may consider objectionable. When imposed without the consent of the user, content control can be characterised as a form of internet censorship.