Mass killings often touch off anguished discussions about what constitutes terrorism. (Our Interpreter columnists addressed these issues in their most recent column). That was evident in thousands of comments across nytimes.com and on social media in the wake of the deadly rampage Monday in Manhattan, which authorities branded as an act of terrorism.

The generally accepted definition of terrorism requires that the violence have a political, ideological or religious motive, as our reporter Scott Shane wrote after the recent attack in Las Vegas. Many readers specifically questioned why that attack wasn’t branded an act of terrorism, and why they believe that label was often linked to religion.

Here’s a selection of comments, which have been condensed for length.

‘The killer of 59 people is labeled a disturbed mind’

“Eight deaths and a person is a terrorist but the killer of 59 people is labeled a disturbed mind. Please explain.” — Terry Thurman, Seattle

‘All of these are acts of terrorism’

“Because a man shouts ‘God is Great’ it’s terrorism? But when a white man has 43 guns in a Las Vegas hotel room, it’s not terrorism? When a white man shoots up a church or a school, it’s not terrorism? Ridiculous. All of these are acts of terrorism.” — Marcia Clearwater, San Francisco