Early one afternoon in November, Internet activity in Bangladesh fell off a cliff.
The drop — to 5 percent of typical activity — lasted only an hour, but traffic would not return to normal levels for weeks. The cause? A reportedly government-ordered shutdown in the wake of a court ruling upholding a death penalty verdict in a high-profile war crimes trial.
The brief interruption was just one recent example of a common problem: Internet disruptions around the world caused by myriad events. Sometimes natural disasters are to blame. Sometimes it's power outages or other technical failures. Sometime the cables that connect the world get cut (on purpose or by accident). And, sometimes, as with Bangladesh, the government just prefers the darkness.
Akamai Technologies, which delivers a sizable share of online content for clients such as Yahoo, IBM and several federal agencies and departments, reviews such disruptions in its quarterly reports, the latest of which was published Tuesday. Here's a look, courtesy of those reports, at the various events and incidents that made the Internet disappear, however briefly, last year.
Bangladesh, of course, isn't the only country whose government has interfered with Internet access.
In Iraq, Akamai recorded a more than 80 percent dip in traffic nine times over the summer, all of them occurring during the same period in the morning. Dyn Research, an Internet performance company that also researches connectivity around the world, confirmed the outages, which were reportedly ordered by the government to prevent, of all things, cheating among students on high-stakes exams.
Last year, in January, the Democratic Republic of Congo cut Internet service to the capital, Kinshasa, in an alleged attempt to contain violent protests against the president.
Doug Madory, director of Internet analysis for Dyn, says such incidents of government controlling Internet access are no longer rare.
"I don't know that I want to say it's more frequent, but when it occurs, people are like 'Oh, yeah, that's too bad, but that's kind of what happens now.' It's not that shocking of a development," he said.
But, he added, exercising such control is getting harder as developing countries become increasingly connected to the world and more and more content gets hosted locally.
"The capacity of the whole system to absorb these incidents and overcome them is also increasing," he said.
Snipped or nicked underwater cables also can take down the Internet for large swaths of time.
A cable-related outage in the West African nation of Gabon resulted in a near-90 percent drop in traffic there over the course of several days in April. The cause, some alleged, was sabotage related to ongoing strikes at Gabon Telecom.
An accidental cut to an undersea cable connecting Algeria and France resulted in a more than 70 percent drop in traffic to the former in October, Akamai reported. Some say vandals cut a cable serving Colombia, resulting in a drop in connectivity there in January 2015.
Late April, Nepal suffered a devastating earthquake. Thousands died, many were injured, and the recovery effort was hampered by the devastation wrought on the country's physical infrastructure.
Immediately, traffic dropped to 11 percent of previous levels, according to Akamai. It recovered, slowly, over the course of several days. While Nepal's connection to the world remained largely intact, local power outages and damaged cables left many within the country with spotty connectivity, according to Dyn.
A month earlier, a cyclone wreaked havoc on the Pacific island of Vanuatu, suppressing Internet traffic for about 36 hours.
Countries will probably never be able to fully eliminate disruptions caused by technical issues, but they can dull their effect with more external connections to the Internet. Some countries, however, are not quite there yet, unfortunately.
Take Azerbaijan. Traffic to the small country situated to the north of the Middle East dipped to 10 percent of normal levels for about six hours on Nov. 16. Why? A data center belonging to Delta Telecom, the country's main Internet provider, caught fire.
Roughly four-fifths of the networks in the country were affected, all of which connect to the Internet through Delta Telecom, according to Dyn.
Such problems don't dramatically affect Internet service in more developed countries, such as the United States, because they tend to be far better connected both internally and externally, Madory says.
"It does require that there's some single point of failure, so to speak," he said.