Remember then? Pennies on the railroad track.

[Ptah]

Not any more:

It's important to be aware of the dangers associated with placing objects on streetcar or train tracks, such as pennies. While a single penny is unlikely to derail a train or streetcar, there are other significant safety concerns.
Risks associated with placing objects on tracks
Becoming a projectile: When a streetcar or train runs over a coin or other small object, it can be launched at a high speed, potentially injuring or even killing someone working or standing nearby.
Damage to tracks or wheels: While unlikely to cause derailment, placing coins on tracks can potentially damage the rail itself or become embedded in the rail or on the wheels of the streetcar or train.
Trespassing and fines: Placing objects on the tracks is considered trespassing and can lead to fines and potential legal consequences, according to Strasburg Rail Road.
Disrupting streetcar operations: Placing objects on tracks could potentially cause delays or malfunctions within the streetcar system.

[hlthe2b]

1. I remember hearing about it, but never got the "why" that people would do so.

[Ocelot II]

4. To make the pennies flat and squished, of course.

[Ocelot II]

2. Heck, yeah! There used to be an ice cream shop along the Mississippi River in Wisconsin

called Flat Pennies Ice Cream - it was right across the road from the BNSF main line to Chicago and kids used to put pennies on the tracks to flatten them. Their ice cream was great but I've heard that they closed recently, alas. The trains still go by, though. https://heavytable.com/flat-pennies-ice-cream-in-bay-city-wisconsin/

[Kali999]

5. Train yards are dangerous.

My mother's grandpa lost his arm working on the railroad.

[ProfessorGAC]

7. My Grandfather Worked On The Railroad

Both in Italy & in Illinois.
He never got hurt badly but he knew many guys that did in the yard & in the roundhouse.
Definitely a danger zone.

[FirstLight]

6. well... I sure all that was true back in the day, there just wasn't the internet to talk about it...

I got to do it once with a friend as a teen in the 80's...it seemed harmless at the time. (I'm sure I put myself in harm's way OFTEN as a kid in the 70's-80's LOL)