Do not equate vandalism with terrorism
I hate vandalism, especially something with communal overtones (such as in Karnataka and Orissa recently). Extreme right-wing Hindu ultra-nationalist organizations seek to do their rabble rousing to remain in the limelight once in a while. Clearly, creating communal tension polarizes the majority voters (hailing from the majority Hindu community) and helps right-wing parties in elections. Even when there are no elections, it is important not to let people forget their base emotions when it comes to India's divisive electoral politics and hence such acts keep happening. When there is a need to pick up lighter issues, they pick on issues affecting freedom of expression (soft targets such as MF Hussain and Khushboo). There have been instances when their actions have resulted in someone getting killed as well. While I don't condone their actions - they must be punished with the maximum allowed penalties for such actions, their actions are just not comparable to terrorism.
However, there has been a move recently by the UPA government to brand antisocial elements of the extreme right-wing in the same category as terrorists - this hyphenation is dangerous, and is in the same vein as the attempt to hyphenate Sarabjit Singh and Afzal Guru to justify inaction on the death penalty confirmed by the Supreme Court on Afzal Guru for the parliament attack in 2001.
The objectives and methods of the extreme right-wingers are very different from those of terrorists. Terrorists and naxals strike at the core of India's integrity and unity as a nation, whereas extreme right-wingers are ultra-nationalists at worst. They strike to maim and kill, carry deadly ammunition with the intention to use it to cause maximum damage, whereas right-wingers almost often are just seeking attention. Much of the cultural policing the extreme right-wingers tend to get into is, while completely uncalled for, is also backed by the so-called Indian centrists and liberals. Terrorists are supported, trained and armed externally (the trend of Indian terrorism is really recent) whereas extreme right-wingers are Indians with a misplaced sense of idealism and nationalism.
I would safely compare naxals and terrorists, more so because naxals have secessionist motives that threaten India's integrity as a nation. They are often as well organized and armed, are these days supported externally, and they strike often to maim and kill. Whatever mass support they enjoyed in the past, the only emotions they elicit these days are fear and hatred. Ultra-nationalists are probably more comparable to the left-wing trade unions, whose power comes from strikes and their power to disrupt work and normal life (through bandhs / lockouts). Their means and motives are similar, often almost altruist, but definitely misplaced, and worthy of censure.