Possessing humility and fear of Heaven, as Chazal say (Chulin 5b), והכתיב אדם ובהמה תושיע ה'” ואמר רב יהודה אמר רב, אלו בני אדם שהן ערומין בדעת ומשימין עצמן כבהמה, one must be careful about the result of one’s words per שמא מתוכם ילמדו לשקר, and other examples.
Someone once went to a rabbi and asked him an awkward question about Arayos, “for an anonymous friend”. The rabbi responded: I don’t understand why your friend had to go to the trouble of sending you in his name when he could just as well have come himself and told me he was asking for an anonymous friend…
Haha! Very clever. (I think the story happened face-to-face, not by letter, per the famous Iggros Moshe and Be’er Moshe: Jews asking what’s worse, Niddah or Goya?) But, now what? Do you think that fellow will ask again? Worse, what about those who merely heard this rabbi at the time, or of this same story later – might they now think twice about asking this rabbi an important question?
This is called being “too clever by half”.