go postal
US /ɡoʊ ˈpoʊ.stəl/
UK /ɡoʊ ˈpoʊ.stəl/
1.
to become extremely and uncontrollably angry, often to the point of violence
:
•
After getting fired, he threatened to go postal on his former boss.
•
The customer started to go postal when his order was incorrect for the third time.