'Will shake foundations of Parliament': Pannun vows response to 'bid on life'

US-based pro-Khalistan terrorist Gurpatwant Singh Pannun threatens action on or before December 13, anniversary of 2001 attack. Pannun responds to India's foiled assassination attempt. Pannun releases video featuring poster with his photo and Parliament attack convict Afzal Guru. Indian security agencies step up security to thwart SFJ operatives. Recent events involve Nikhil Gupta, Taranjit Singh Sandhu, Vikram Doraiswami, and Hardeep Singh Nijjar. Pannun's anti-India campaign ongoing for 2 years. Pannun's outfit, Sikhs For Justice, involved in aggressive actions globally.