Many tasks can be safely killed. It is up to the coder of the task to implement friendly murder.
Just give a task a ctrl-c
Many tasks kill themselves when they get a ctrl-c.
If you started the task from the current shell, just type ctrl-c in the shell window.
If the task started some other way then find its cli number, lets say it is cli 4. Type in the shell:
break 4 c
It can't hurt to try.
