Difference in the parameters. If immoral activity suddenly isn't immoral or rather "okay" if executed by an "institution" how can a (so called) "terror Group" b

Difference in the parameters. If immoral activity suddenly isn't immoral or rather "okay" if executed by an "institution" how can a (so called) "terror Group" be judged differently? Why are they responsible for the institutional actions while other institutions (or the people behind them) are not?