It all started with a simple e-mail encouraging New York University students to opt for the paperless, electronic delivery of their 1098-T tuition form this year.

Unsure of what he should do, sophomore Max Wiseltier figured he should probably ask his mom for advice. But his harmless inquiry, "Do you want me to do this?" was inadvertently sent to every single student at NYU on the list — all 39,979 of them — prompting a campus-wide discovery that any student could "reply all" with whatever they wanted.