It is narrated from Sayyiduna al-Sa'ib bin Khallad (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "O Allah, whoever wrongs the people of Madinah and frightens them, then frighten him; and upon him is the curse of Allah, the angels and all of mankind. Allah will accept from him neither voluntary worship nor obligatory."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6606