Anders Behring Breivik, the man who killed 77 people in a rampage in Norway last summer, was sentenced Friday to 21 years in prison by an Oslo court. The sentence is the maximum allowable time under Norwegian law, and Breivik will likely stay in prison as long as he’s considered a threat.

However, the decision still prompted controversy online as some have suggested that the term is too lenient for a man who gunned down children and has shown no remorse.

After the ruling, Breivik apologized to “militant nationalists” for not killing more people.

BREAKING: Breivik apologizes to ‘militant nationalists’ for not killing more during Norway attacks: -SC

— The Associated Press (@AP) August 24, 2012

View Photo Gallery: Anders Behring Breivik got a 21-year prison sentence for bomb and gun attacks that killed 77 people last year.

Breivik, who killed 77 people, sentenced to 21 years. How many children to you have to kill to get a life sentence? What’s the rule here?

— Dean Leysen (@DeanLeysen) August 24, 2012

Is the death penalty cruel and unusual? I would say 21 years for Breivik is cruel and unusual to the victims and their families.

— john william (@john_william) August 24, 2012

Norway sentenced mass killer to jail for 21 years. Since he killed 77 people, he is serving less than 4 month/kill.

— Finn (@_finn) August 24, 2012

Others said Norway’s unusually humane prisons are too good for Breivik. He will be kept in isolation and restricted to three cells: One with gym equipment, one with a bed and a third with desk and laptop computer.

Anders Breivik’s “suite of cells” with office, gym etc sounds better equipped than his home. Hardly a punishment for his hideous crimes

— Jane Moore (@JaneMooreSun) August 24, 2012

Norway does not have the death penalty, but the sentence could be extended as long as Breivik is considered to be a threat to society.

Rather than a typical jail term, Breivik was sentenced to “preventive detention,” which means it’s unlikely he will ever be released, the Associated Press reported.

Several survivors of the attacks and relatives of victims said they supported the ruling.

“I am very relieved and happy about the outcome,” Tore Sinding Bekkedal, who survived the Utoya shooting, told AP.

One Norwegian lawyer suggested that the sentence was more than adequate:

To those ridiculing #breivik’s preventive detention sentence (… ); how are crime rates in your countries, in comparison?

— Jon Wessel-Aas (@jonwesselaas) August 24, 2012

Of course, it’s best to take the theories of Twitter pundits with a grain of salt, as one user did:

This is all I have to say about the Breivik sentencing:…

— Becky Jones (@BeckySJones) August 24, 2012

More world news coverage:

- Grisly killings mark violent surge in Damascus

- Colombia author recounts father’s murder

- U.S. journalist is missing in Syria

- Read more headlines from around the world