Does Dissent Make You An 'Urban Naxal'?

On the eve of the first round of elections, with Chhattisgarh voting in Phase 1 on Monday, Prime Minister Narendra Modi talks about "Urban Naxals" for the first time, saying they sit in AC rooms and remote control tribals. He accused the Congress of shielding them, but who are 'urban Naxals' anyway? Are they really Maoists seeking to overthrow the state, or is this a term being used to hit out at anyone who dissents against the government?