Coffee, I’ve learned, is a hot topic. After last week’s column on my encounter with a guy who wouldn’t stop sipping from his mug on Metro, I got emails, calls, tweets and even a minor threat. (Buddy, seriously, I think it’s time to cut back on the caffeine.) So before heading on to another topic, I’m pausing here momentarily to share some of your responses.

-Several readers wanted to let me know that when they see something, they also say something. It’s an approach that gets a mixed response. “I’ve told more than my fair share of people that eating and drinking is not permitted on the train, and they look at me like I have a third eye,” reported Mark Size. Once, Lois Steinberg reminded a woman about the rule, and when the woman just kept on eating, Steinberg quipped, “You must be a lawyer.” “No, a law student,” the diner responded.

Patrick Ney made the case for why coffee drinking deserves an exemption to the no-eating-or-drinking rule. The ban “is a decent idea being taken too far. I think the ability to drink coffee in the train is simply more important than the need for absolute cleanliness,” he argued. “I will take the sight of an occasional rat any day over a non-caffeinated commute.” He invites police to come find him at the Chinatown station at 8:10 a.m.

-“Metro-riding rule breakers abound. I let this one go, but still captured the moment,” tweeted Jim Darling. It was accompanied by photographic evidence, showing a woman stuffing her mouth while squeezing a soda can between her legs. Maybe eaters and drinkers will ignore complaints from other riders — and maybe Metro doesn’t have the staff to adequately police behavior — but a public shame campaign has potential.

Geoffrey Patton found someone setting a really bad example: a Metro employee eating chicken fingers. But he didn’t call her out on it, because he was focused on another problem. Despite reporting it last week, Patton keeps seeing (and smelling) a dead opossum on the tracks at College Park. “Another few days,” he wrote, “and no one will be able to eat on that branch of the Green Line.”