Frontline police are right to be concerned about the confrontational turn some recent protests have taken. But they are wrong to demand a new law banning foul language. Some officers were particularly offended by banners at two recent protests with the slogan in English, 'F*** the police'. The protesters were upset at the heavy-handed way police power was deployed during the visit by Vice-Premier Li Keqiang last month. The latest reaction from the police marks another escalation. At least two police associations have come out to demand new legislation outlawing the use of foul language against officers while performing their duties. For a long time, protests in Hong Kong have been noisy but peaceful. Most remain so today. But there have been some disruptions that show worrying signs of both police and protesters ready to take their confrontations to a more violent level. One side says police and the government are using increasingly restrictive measures to silence demonstrators. The other side says young protesters are more radicalised and violent. It's time to step back. Police already have the power to make arrests on such occasions under the charge of disorderly behaviour, regardless of whether foul language is used. Swearing is also illegal on public transport systems, including in taxis and minibuses. It would therefore be exceedingly odd to have a separate law against swearing only at police officers. In any case, Hong Kong police already have enormous powers to make arrests. We should not hand over more power that could easily be used as an excuse to arrest almost anyone.