WHEN DID IT BECOME "OKAY" TO.....

Let's open this one to discussion....fill in the blank: 
"Can someone please tell me, since when has it become acceptable to _______________ in public?"

I'll start things out:  "....okay to clip your fingernails in public?"  I was on the Downtown "A" train, which runs express from 125th Street to 59th Street in Manhattan, which is about 10-15 minutes, meaning if you're in a miserable car (no heat/AC, god-awful pan-handling musician, dead passenger next to you, etc.) you're trapped for a nice, long stretch.  This guy next to me takes out a pair of nail clippers and starts clipping away, letting his goddamned clippings fly wherever they flew.  Even with my headphones on with the Mahler Resurrection Symphony at high volume, that piercing metallic "SNAP" penetrated my brain.  With each SNAP, my blood pressure rose 10 more points....but I was not in the mood to have it out with this slob, so I tried valiantly to ignore it....SNAP..........SNAAPP!  No one else in the car seemed to acknowledge him (T.S.A.S.:  Typical Subway Anonymity Syndrome, I believe it's called).  Fortunately, I was getting off at 59th, so I didn't have to suffer this scenario all the way to Brooklyn or anything.  For something as mundane as nail-clipping, I somehow found it grossly disturbing to witness on mass transit.  I mentally vowed that I would physically attack him if he removed his shoes and started in on the toes, I swear I did. So, I'd really like to know:  Is it really acceptable to do this?  I think I know the answer....your thoughts?  And your own answer to the question as well...