OK, I'm talking mostly about Awareness rolls, since most other failed rolls it's pretty easy to say "you can't think of anything" with Lore or "you fail to overcome the safeguards" with Security. With Awareness though, the GM simply calling for the roll makes players think that something is out there to be noticed; if they succeed, they will obviously expect to be told some info and if they fail, the players know that they're missing something and it can bleed into IC.
If they roll openly and fail, they will know OOC that they missed something; they can sit on it (but risk metagaming where OOC they know they missed something, which can bleed to IC suspicion) or Fate it for a reroll.
If the GM rolls for Awareness secretly, the GM can easily tell the people who passed the roll if their characters notice something (the implication being that those who failed did not notice/don't get told they notice anything), but if you roll secretly for Awareness, those who failed theoretically lose the opportunity to call a Fate reroll. Then they know they failed some roll, they didn't have the chance to Fate it, and they suspect they missed something, leading to the same OOC-to-IC bleed. And maybe some resentment since you took away their chance to reroll it.
This happened with me last week; in the sake of time, I rolled secretly. One of the players later brought up "if I had known there was a roll and I knew I failed, I would have Fated it." I recognized the problem, just wasn't really sure how to address it. Awareness and maybe Navigation seem to be the only things that this would really affect, though I could be wrong on that.
Just wondering how other GMs handle it.