One tweet put it more bluntly: "Dunblane,1996. 16 dead kids+adult. 1.2 million sign petitions. UK govt. enacts new law. Halts private guns. Tag, USA. You're It."
In that same year, a 28-year old Australian killed 35 people with two semiautomatic rifles in just eight minutes. Then-Prime Minister John Howard pushed through a law that banned assault weapons and instituted a gun buy-back policy. (Some 650,000 were taken out of circulation.)
Howard recalls telling an audience in Texas in 2008 that the law was among his proudest achievements in 12 years as prime minister.
"There was an audible gasp of amazement," he wrote in an op-ed this year in The Sydney Morning Herald.
After the mass shooting in Aurora this year, Howard said he was not optimistic it would change anything.
"The responses of President Barack Obama and Mitt Romney ... were as predictable as they were disappointing," he said.
"There are many American traits which we Australians could well emulate to our great benefit. But when it comes to guns we have been right to take a radically different path," Howard concluded.
Australian-born media magnate Rupert Murdoch chimed in Saturday on his Twitter account: "When will politicians find courage to ban automatic weapons? As in Oz after similar tragedy."
Some columnists don't detect any popular pressure in the United States for change, even if the gun control debate has flared in the wake of the Sandy Hook shooting.
Mirjam Remie, who writes for the Dutch newspaper Handelsblad, observes that "support for stricter gun laws has been steadily declining for decades. According to Gallup, it is 44%, but twelve years ago it was 66%."
Debate rages about the relationship between the availability of guns in society and the number of deaths caused by guns. But the laws enacted in the UK and Australia sharply restricting gun ownership do appear to have made a difference.
A study (PDF) by researchers at Harvard University in 2011 found that in the 18 years before the new law was enacted in Australia, a total of 13 gun attacks had led to four or more fatalities. In the 16 years since the new law, the number was zero. Individual homicides involving guns have also fallen.
Japan has some of the most restrictive regulations in the world on gun ownership. Shotgun licenses for hunting require a lengthy application; handguns are forbidden. Homicides by gunfire in Japan rarely get into double figures in a year.
In the view of author David Kopel, who has studied Japan's gun control laws in great detail, its regulations work because they are "part of a vast mosaic of social control ... a pervasive cultural theme that the individual is subordinate to society and to the government."
That would not be acceptable in the United States. Even so, while recognizing the power of the Second Amendment, foreign commentators are not shy of recommending what could and should be done to tackle gun violence in the U.S.
In the UK, The Guardian editorialized in the wake of the Newtown shootings: "A proper federal system of regulation, including background checks registration, and limits on the type and number of weapons an individual can own, would bring the U.S. belatedly into line with other civilized countries, as would a determined push back against state legislation allowing the carrying of concealed weapons in public."
Hours before the Sandy Hook massacre, Michigan lawmakers passed legislation allowing those with concealed pistol licenses to carry guns into schools, hospitals and churches among other places.
In the words of one commentator: "No society that holds itself up as an example to the world should, as the United States does, brazenly shrug off what are clearly deep national character flaws when it comes to our love of guns or our celebration of hate politics."
The writer was not a foreigner, but an American -- David Rothkopf -- writing in Foreign Policy. And he was writing not this weekend, but after Jared Loughner shot and killed six people, and injured more than a dozen, including U.S. Rep. Gabrielle Giffords, in January 2011.