freely sift through user text

Networking sites want you to feel that you have control over who sees your personal information. However, the reality is quite different as sites are now being used as surveillance tools. Growing numbers of campus authorities, HR departments and local police freely sift through user text and photos to monitor behavior and to investigate crimes.

To begin with, "user text" sounds really odd to me. I'd prefer it reads "users' texts" or "user texts?"

Second, could I replace "monitor" in the above with "watch/survey/supervise?" Thanks.

User text seems fine to me, Angli.  Text is uncountable here, and the noun-as-adjective (user) usually works better than the possessive in impersonal communications.

Monitor is the standard word choice here, for 'watch on an ongoing basis'; survery and supervise are wrong.