On Twitter, someone posed this question: “Who put Costas on in the middle of a football game so he could spew his one sided beliefs?” Another tweeter sharply recommended Costas “stick to football … the more you talk, the dumber you sound.” And on and on it went. The message resounded: Bob Costas, just shut up.

All from this: “If Jovan Belcher didn’t possess a gun,” Costas told a TV audience of more than 20 million, “he and Kasandra Perkins would both be alive today.”

The reasons for the pushback were familiar when a celebrity — be it musician, sportscaster, even news anchor — bypasses what the public believes is that star’s area and expounds on issues in the larger world. But as our world grows into a place where anyone with a smartphone and an Internet connection can rant far and wide, celebrities, it seems, are still held to a higher standard — or a different one — than the rest of us.

Reaction to Costas’ remarks was swift, with much of it harsh, ranging from the scolding hosts of Fox News Channel’s “Fox & Friends” the next morning to agitated sports fans typing tweets as they watched him on NBC’s broadcast of the Philadelphia Eagles-Dallas Cowboys game.

Numerous reasons were advanced for why Costas had no business weighing in on the issue of gun ownership (while others expressed their support for him).

But in an odd lapse of reasoning, many of the opinion slingers who condemned Costas blasted him for simply voicing his opinion.

Technology has leveled the playing field (so to speak) for distributing opinions and ideas to the world. Granted, most people don’t have 20 million listeners at their command, as Costas did Sunday. But everyone can post a comment on any topic that, via social media, can reach a global audience.

Consumer feedback is solicited by media outlets and other organizations around the clock. A public forum for opinions that can span the world is guaranteed anyone in reach of a Wi-Fi connection.

And yet, in an era when widespread opining is deemed our basic human right, an opinion that is often leveled at others for doing so is “You should shut up!”

With that in mind, much debate surrounding Costas’ commentary has sought to tease out a distinction between acceptable opinion and opinions that are out of bounds.

It’s been said that politics and religion don’t mix. But the response to Costas’ commentary suggests that, for many within earshot, sports are even more sacred.

By this argument, a fractious world of partisan politics and cultural clashes has no place in the football sanctuary. Sports should be a refuge from life’s harsher truths, a comfort zone for a special brand of clashing between rival teams. Here, Red State/Blue State differences can take a break and unite for a red-white-and-blue brand of partisanship.

So when politics encroaches on sports, it inevitably makes some fans queasy. Or livid.

Just recall President Jimmy Carter’s controversial decision that the United States would boycott the 1980 Moscow Olympics after the Soviet invasion of Afghanistan. And at the 1968 Olympics in Mexico City, two U.S. athletes raised a black-gloved fist in a black power salute during the medal ceremony. The two African-American athletes were expelled from the Games.

If Costas played politics for 90 seconds Sunday night, it was on a much reduced scale than those examples.

Yet many people “insist that an NFL broadcast is supposedly a sacrosanct and therefore apolitical space that must remain free of ‘hot-button issues,’” noted David Sirota in a Salon column on Tuesday. “But, then, in commenting on the Kansas City Chiefs murder-suicide, Costas was merely weighing in on the biggest NFL story of the day, which is exactly what he’s paid to do and what typically happens during an NFL halftime show.”

Were Costas’ reflections on when “ugly reality intrudes upon our games” really so intrusive and outrageous?

Did his status as a professional commentator really disqualify him from sharing a thought about a tragedy that millions of his fellow Americans were talking about?

Should he really lose his job? (That was an opinion voiced on Fox News Channel.)

“What I was talking about here — and I’m sorry if that wasn’t clear to everybody — was a gun culture,” Costas said in an appearance on MSNBC’s “Last Word with Lawrence O’Donnell” on Tuesday. “I never mentioned the Second Amendment. I never used the words ‘gun control.’ People inferred that.”

Even so, it may be that Costas crossed a line by bringing politics into his football coverage.

But it wasn’t the first time a hot-button issue had been pressed in a sports broadcast. In 2003, conservative radio superstar Rush Limbaugh resigned from a brief stint on the panel of ESPN’s “Sunday NFL Countdown.” His departure followed his race-tinged comments about Eagles quarterback Donovan McNabb.

“Sports people say they don’t want any politics involved,” Limbaugh said in a Tuesday commentary addressing the Costas affair (where he cracked “I don’t blame Bob Costas. I blame the microphone”).

Limbaugh said there had been no provision in his deal with ESPN not to bring up politics. “But I never asked to be able to, either. It wasn’t even on my mind.”

Keeping sports and politics in separate spheres may be less and less possible in a world that breeds opinions and crossbreeds its performers.

In his Salon column, David Sirota noted that boundaries are disappearing between sports, culture, entertainment and politics: “Modern America is a place where an actor can become president, a pro wrestler can become a governor, a football player can become a congressman, and a comedian can become a U.S. senator.” And (as he could’ve added) where a real estate mogul can become a TV host, political pundit and prospective presidential candidate.

Meanwhile, everyone is talking, with Costas only one among the chattering multitude. And that, of course, means there’s a danger of less and less time being set aside for listening.