In November 2010, Crown Court judge Jacqueline Davies, sitting with two magistrates, dismissed Chambers' appeal, saying that the electronic communication was "clearly menacing" and that airport staff were sufficiently concerned to report it.
Today, the Lord Chief Justice Lord Judge, sitting with Mr Justice Owen and Mr Justice Griffith Williams, said:
We have concluded that, on an objective assessment, the decision of the Crown Court that this 'tweet' constituted or included a message of a menacing character was not open to it.
On this basis, the appeal against conviction must be allowed.
More top news
A shock to the system
We found a tableau of desperation; vast crowds of people pushing and shoving their way forward, away from the continuing bombardment.
Cambridge Analytica played a key role in mapping behaviour of voters in the US election and was used during the EU referendum campaign.