> Deliberately depriving people of information is not ethical.
Misleading people is unethical. Providing incomplete information is misleading.
80% of Americans say they want labels on food warning if they contain DNA[0]. Not because people fear DNA, but because when you ask, that signals that DNA is potentially bad. Actually providing such a label is also a signal that DNA is bad.
Labeling food with "Warning: contains DNA" is unethical because it misleads people into thinking that's bad.
Adding a label saying "DNA-free" is unethical because it's false, unless you're selling salt. (And probably also misleading: https://xkcd.com/641/ )
But failing to provide such a label? Not misleading, and not unethical.
If someone asks "does X phone home, does Y contain DNA", you should answer honestly, but you should probably also provide explain the pros/cons. Granted, unless you planted the idea in their heads, that's not your responsibility, but if you publish an article saying "Food X contains DNA!" or "Plugin Y phones home!" you _are_ responsible for the resulting fear, and should qualify the information with an honest evaluation of what that means.
[0] http://www.washingtonpost.com/news/volokh-conspiracy/wp/2015...