Q: Who made the case?
A: Three councillors and one senior official: Ian Malcolm, the council's Labour leader, David Potts, former Conservative group leader who is now an independent, Anne Walsh, a Labour councillor, and Rick O'Farrell, head of enterprise and regeneration, took the case to a Californian court.
Q: Why did this case work while others failed?
A: The court was able to force Twitter to release the information as it is an American court and has jurisdiction over the US company.
Q: Why did a previous bid by Premier League footballer Ryan Giggs fail?
A: Because Mr Giggs' legal team used the British court system to attempt to force Twitter to release the information, but it was found to have no power to order an American company to release information, even if the alleged offence took place in Britain.
Q: What is the likely impact?
A: Legal experts believe we are likely to see more cases of people taking suits to the US court system to force Twitter and other such sites to reveal the identities of those committing offences such as libel.
Q: Is this the end of freedom of speech for the internet?
A: Some believe it will clean up the internet, where people have been able to defame others with false allegations anonymously, without any punishment.
This would then bring the internet into line with other media, where strict laws of defamation and contempt of court apply.
However, others fear that the rich and powerful will be able to use this legal precedent to gag genuine accusations and to allow them to cover up truths they would rather remain hidden.