This week, we have been looking at contact tracing apps using the decentralised Apple Google toolkit which the NHS in England has now adopted. We concluded there was little evidence they were working because no country could supply data showing how many people had received alerts telling them they may have been in touch with an infected person. We were, however, still awaiting a response from Ireland's health service. Now they have come back with some data. In the two weeks since the Covid Tracker app was launched, 91 users have received a "close contact exposure alert" – in other words, they have been told they have been in contact with another user who has tested positive for the virus and should get tested themselves. Now there is still a lot we don't know – how many of these contacts were the kind that would not have been picked up by manual tracing, how many of them went on to test positive. But what is interesting is that Ireland has got any data at all - Germany and Switzerland told us the nature of the decentralised system made by Apple and Google meant they could not know how well their apps were working.

TikTok blocks hashtags of QAnon conspiracy theory

TikTok has blocked a number of hashtags related to the QAnon conspiracy theory from appearing in search results, amid concern about misinformation, the BBC has learned. QAnon is a wide-ranging, unfounded conspiracy theory whose followers support US President Donald Trump. TikTok said it moved to restrict "QAnonTruth" searches after a question from the BBC's anti-disinformation unit, which noticed a spike in conspiracy videos using the tag. The company expressed concern that such misinformation could harm users and the general public. "QAnon" and related hashtags, such as "Out of Shadows", ''Fall Cabal" and "QAnonTruth", will no longer return search results on TikTok - although videos using the same tags will remain on the platform. Videos using the "QAnon" hashtag, in particular, have millions of cumulative views and can still be found if a user's algorithm directs them to the associated content. TikTok's intervention comes after Twitter announced measures earlier this week also aimed at cracking down on the QAnon conspiracy theorists, including banning thousands of accounts.