That's painful. Granted, she is a public figure - and her insinuation was about something incredibly offensive and serious - but the case highlights critical points about social media use that apply universally.
As comms specialists, and therefore influencers, you are some of the most likely to be social media users in your personal as well as professional lives. If there was ever any doubt, the judgement makes clear that your words are subject to libel law, just as when in print.
Emoticons carry meaning. The judge, far from being social media illiterate, had no difficulty in finding that the intention behind her use of 'insincere and ironical' language was to link Lord McAlpine to the allegations. Using the word 'trending' acted as a signpost, pointing followers in the direction of the other key information - the paedophilia allegations. The case makes clear that innuendo is as dangerous in social media as in print. If your meaning - whether implicit or explicit - is reasonably likely to be understood to be defamatory, tread (or tweet) carefully.
Emoticons are like Marmite, but love them or hate them, think twice before dropping them in.
It is easy to drop your guard when using a real-time medium like Twitter. You want to keep your followers engaged and be part of the conversation, especially if it's a fast-moving story. Check what's trending and don't forget it's an open forum. Would you say the same in a mass email, or in a letter to The Times? If not, stop.
Equally, when monitoring Twitter for a client, adopt the same strategy. Is the tweet the final piece of the jigsaw that identifies or links your client to the allegation? Also remember, Twitter being US-based and therefore First Amendment-minded makes it difficult to get content taken down.
It's worth remembering that many tweeters have more followers than today's papers have readers. The damage done online can be just as great, if not greater in the Twitter age. Just ask Sally.
Julian Pike is head of reputation management at law firm Farrer & Co