But the Latin is so bad it doesn't appear even to be Latin. Admittedly, it's been a long time, but I majored in this stuff. "Uti" and "si" are Latin words, though you'd expect "si" at or near the beginning of the sentence, not at the end.
"NSA" isn't Latin, obviously.
Which leaves us with the curious "im" and "cu." Google Translate sure thinks they mean "I" and "wish," respectively, but that seems like a real stretch to me. The pronoun "I" in Latin is declined ego, mei, mihi, me, me. The closest I can get to "im" meaning "I" is that it's a first-person singular irregular suffix for "be" verbs in the present subjunctive (e.g., "sim"). Here, it's not attached to a verb--it's just hanging out in the sentence.
"Cu" is no less opaque. I think Google Translate is tying it to cupio, which indeed means "want" or "desire," but it's not actually a form of that verb. And if I'm remembering right, cupio is generally more along the lines of greed or carnal desire rather than a preference or wish (for which, again if I'm remembering right, you'd use volo, velle).
And add to that the fact that even the Google Translate translation doesn't really suggest what this author wants it to suggest. "If you want to use the NSA" makes no sense on its own as a warning, and it also doesn't make sense when appended to the sentence: "Using TrueCrypt is not secure as it may contain unfixed security issues if you want to use the NSA."
There's plausible deniability and then there's obscurity beyond all reasonable bounds. If they were trying to go for the former, they've veered WAY over into the latter territory.