There are some specific words for certain deeds like when someone give us gift we say "jazakAllah". Then what should I say when I see bad deed.
whenever we see bad deeds first of all we shuold try to stop them.
On the authority of Abu saeed al-khudree(ra) who said: "I heard the messanger of ALLAH (saw),"whosoever of you sees an evil,let him his hand;and if he is not able to do so then[let him change it] with his tounge; and if he is not able to do so'then with heart -and that is the weakest of faith" [MUSLIM]
or we shold say "NAUZBILLAH" WHEN see the bad deeds. and shold also pray that:
"allahahuma innee auudu bika min munkaraatil-alkhlaq, wal-amaal wal-ahwaa.(sunan ATTERMIDHIY#3591.
"O ALLAH!I seek refuge in you from reprehesible deeds and whims"