The myriad protests and demonstrations that take place in the city every year are often seen as evidence of the freedom we enjoy under the "one country, two systems" policy. It is no exaggeration to say that hardly a day goes by without groups taking to the street for different reasons. Like it or not, some roadside campaigns have existed for so long that they literally become part of the streetscape in neighbourhoods. While the community is by and large used to such activities, there are growing concerns that some have become increasingly disturbing. The escalating banner war against Falun Gong, a spiritual group outlawed on the mainland, is a cause for concern. The Hong Kong Youth Care Association has the same right as the Falun Gong to express its opinions. As long as members abide by the law, their right to demonstrate should be respected. That said, the right should be exercised in such a way that the impact on others is kept to the minimum. What the spiritual group preaches may not be accepted by everyone. Some may even deem its presence in crowded districts a public nuisance. But that does not mean opponents can seek to drown it out by putting up larger banners over the ones displayed. The walls of banners in some pedestrian zones have obstructed public space and become an eyesore. Such provocative tactics may also fuel confrontation and go beyond our culture of protesting in a peaceful and orderly way. Self-restraint from both sides is called for. According to the government, the street campaigns by Falun Gong and the association fall under a publicity display scheme managed by the Lands Department. But how can the groups continue for so long without seeking permission, as required? Lawmakers were told last month that the police had been alerted amid concerns that the banner war might jeopardise the safety of pedestrians and motorists. Regrettably, no action has been taken so far. The authorities should step in immediately lest the situation worsens.