Complaints of crimes involving Facebook and Twitter have increased 780% in four years, resulting in around 650 people being charged last year, police figures show.
The phenomenon of social networking crime was comparatively minor in 2008 with 556 reports made to police, according to the statistics released by 29 police forces in England, Scotland and Wales under the Freedom of Information Act.
But this year 4,908 offences in which the two sites were a factor were reported.
Lancashire Police received reports of six threats of murder via social networks
Chief Constable Andy Trotter, the Association of Chief Police Officers' lead on communications, said the figures demonstrate a new challenge.
It is important that forces prioritise social networking crimes which cause genuine harm, rather than attempting to curb freedom of expression, he said.
"It is a new world for all and we could end up in a situation where each constabulary needs a dedicated Twitter squad. In my opinion, that would not be a good use of resources in difficult financial times.
"We need to accept that people have the right to communicate, even to communicate in an obnoxious or disagreeable way, and there is no desire on the part of the police to get involved in that judgment.
"But equally, there are many offences involving social media such as harassment or genuine threats of violence which cause real harm. It is that higher end of offending which forces need to concentrate on."
Police forces were asked to provide the number of crime reports in which either Facebook or Twitter was a key factor. This included offences committed on the sites, such as posting abusive messages, and those which were provoked by postings, including violent attacks.
A total of 653 people faced criminal charges over the allegations this year, according to the forces which responded.
Great Manchester Police charged the highest number of people, at 115.
In 2008, 46 people in all force areas were charged in cases connected to the sites.
Some forces also released a detailed breakdown of crime reports. This showed a wide variety of offences, with harassment and menacing messages among the most common.
For example, Tayside Police received 66 reports involving the sites this year, 44 of these involved sending obscene or menacing messages.
In Merseyside 21 of the 76 crimes reported this year involved harassment.
There were also numerous sexual offences including grooming, complaints of stalking, allegations of racially aggravated conduct and reports of fraud.
Trotter said offences can be roughly divided between crimes which would have been committed, albeit in a different way, before the emergence of social media and those which exist because of the online platform.
"There is an issue of public expectation," he said.
"We have to respect free speech and cannot have police forces responding simply because of public outcry.
"In many ways, online communities can be self-regulating and good at weeding out unacceptable behaviour. We need to find a way of distinguishing between that type of behaviour and that which requires police intervention."
He welcomed recent guidance from the Crown Prosecution Service (CPS), saying it set a "high threshold" for that intervention and represented a first step towards a better coordinated approach.
Director of public prosecutions Keir Starmer QC announced the new guidelines on how people who post offensive messages on Facebook and Twitter should be dealt with. The guidance is expected to result in fewer criminal charges being brought.
The May 2010 conviction of Paul Chambers for joking on Twitter about blowing up Robin Hood Airport in South Yorkshire is a well-known case.
His conviction for sending a "menacing" tweet drew widespread condemnation and was eventually quashed on appeal in the High Court in July.
Admitting that the CPS made the wrong "judgment call" in this case, Mr Starmer said: "In most cases, once you have put the (new) safeguards in place then a prosecution is unlikely to be the appropriate response.
"To that extent, therefore, it is to make it less likely that these cases will be prosecuted."
Other high-profile cases include nine people each ordered to pay the woman raped by footballer Ched Evans £624 for naming her on Twitter or Facebook.