I suppose the Latin phrasing needs to be double-checked, but it's nice to have what we ought to aim expressed to concisely (even in English). I guess the Latin makes it sound more serious and authoritative (but also more cryptic, so it's a double-edged sword to manipulate with caution). May it help spread the spirit, with which I completely agree. Kudos for aiming this.
Getting into a rhetoric style, rule of thirds can help. So something like: Custodi usorem, custodi data, custodi veritatem.
Usorēs, data et veritas primum
Users, data and truth first.
And actually first in the sentence structure (in both languages).
(edit: I had initially used prima - neutral plural nominative for primus (adj.) to target the three subjects, which I don't know if it's right, but using the adverb feels better. I don't do Latin though)