gregmcc
Honorary Master
https://www.bbc.co.uk/news/technology-46466530
A Google training exercise that went wrong meant a dummy advert was placed on a "huge number" of webpages and apps, the Financial Times has reported.
The mistake meant a blank yellow rectangle was active on the sites and apps for about 45 minutes on 4 December, it said.
The ad was only visible to people in the US and Australia.
The mistake happened when trainees were being shown how to use Google's in-house ad placing system.