Scotland's Chief Constable Sir Stephen House has declared a rise in abusive behaviour on social media is replacing traditional forms of vandalism.

Sir Stephen pointed his finger at the popular micro-blogging site Twitter, which he says is allowing users to vent their anger online rather than in the traditional form of vandalism that involved spray-painting angry comments on walls and bus shelters.

Twitter claims to have 15 million users in the UK, and 500 million globally. Launched in the US in 2006, it allows people to send and receive text-messaged sized statements - or "tweets" - of no more than 140 characters.

Questioned at a meeting of the force's oversight body, the Scottish Police Authority, on why traditional antisocial behaviour crimes were on the wane, Sir Stephen said: "Social media in some instances has replaced graffiti as a way of making your views heard. We have had to deal with offensive comments made on Twitter. My view is that 10 to 15 years ago, that would have been sprayed on the side of a building."

Vandalism, fire-raising, malicious damage and related crimes have been falling dramatically in recent years. There were 13,453 of such Group 4 offences, most of which are against property, in April-June 2014, the first quarter of this financial year.

That was down nearly eight per cent on the same period a year before. But the figure has more than halved since 2009-10, when it stood at 28,146.

Challenged on why this was, Sir Stephen did not just blame the ­transition of abuse from graffiti to Twitter. The downward trend in the figures, he said, probably deserved to be studied for a university thesis.

The chief constable took some of the credit for his own force - and its predecessors - for focusing on "local policing and high-visibility patrols".

He said: "We have seen a significant drop in anti-social behaviour and we see fewer complaints of drinking in public complaints. Some of these things tend to go with vandalism, graffiti and damage to property." Downplaying suggestions that public apathy had led to fewer calls to the police about vandalism, Sir Stephen stressed societal changes. He praised architects and designers for helping to make it harder to commit vandalism - and harder to break things.

"I think we should also give credit to intelligent design as well," he said. "Things are harder to vandalise than they used to be. It is most cost-effective to build something that is difficult to vandalise, say a bus shelter, than it is replace it.

"We have a lot of success against gangs. Some of it has been that the Xbox and PlayStation generation is less of a gang generation. They are not out in the street so much. You can correlate that with things like the general view that youth fitness is not where it was. Why? Because they are not out ­playing football to all hours of the day and night. They are inside on the Xbox, But if they are not outside, they are not doing the damage.

"But that takes us back to social media, people staying indoors may be committing some sorts of crimes like cybervandalism, but it is not visible to the rest of the community."

Police can and do investigate Twitter crimes - although a recent investigation of racist abuse against an Irish-born Glasgow SNP councillor, Feargal Dalton, fell through after officers failed to obtain information from the social media giant.

Sir Stephen stressed that abuse was abuse wherever it occurred. "When challenged, some people say 'I didn't say that, I put it on Twitter'. Well, it is the same as saying it."

Police Scotland itself has invested heavily in its own social media presence. It reported to yesterday's meeting in Clydebank that it now has 571,610 followers on Twitter. That represents a rise of four per cent over the summer.