These type of images inspired Pete Malachowsky to start the Twitter account N_Train_Gossip last month.
"When I hold it, I basically hold it down," Malachowsky said.
No one knows he's taking their picture with his iPhone and tweeting it across the internet.
"I'm not the only person that's noticing these things on the train. I'm just the only person calling people out on it," he said.
But other pictures make bolder statements on human nature.
One picture shows a homeless man who took off his shoes.
Another tweet is titled "Nose Picker." It's self explanatory.
If someone was taking you're picture, you would you think you would know it. But dozens of people have ended up on this website, and don't have a clue.
"Probably not, because I really don't pay attention," Caitlyn Brown said.
In fact, not all N line riders even know they're the potential subject of the tweets.
Kate Beahen has never heard of it and said she would not want her picture used.
"But then again I don't do anything rude on the subway, I don't think. I mind my own business. I keep my shoes on," she said.
Some commuters don't find it funny at all. There's a counter-offensive twitter account called NTrainstrikesBK.
"You're on public transportation. I understand that you might be doing things. Don't do it on the train where I can see you do it," Malachowsky said.
If you do, you might just end up on the internet.
ON THE NET: