Some students and writers collaborating on shared documents via Google's cloud services found themselves temporarily locked out of their files yesterday, and were told it was because their content violated Google's user policies.

The issue, since resolved, was blamed on a code update that "incorrectly flagged a small percentage of Google Docs as abusive," according to a help forum post by Google Docs community manager Julianne Niemaszyk. She added that Google "will put processes in place to prevent this from happening again."

However, the incident highlights another Google practice that raises security and privacy concerns: its automated scanning of content that's shared by users in the cloud. For instance, for advertising purposes, Google robots have habitually scanned messages sent using the free consumer version of Gmail, although the company announced in June that it will stop that practice later this year.

'This Kind of Monitoring Is Creepy'

Yesterday, a number of users began posting questions on the Google Docs Help Forum about being locked out of files they were sharing online, or about discovering that shared files had been deleted. One early post reported that "my colleagues and I are working on a very important document for our college course and whilst we were working on it, the system has kicked us out of it and deleted it," adding that no reason had been given for the lockout.

Other users reporting similar issues noted they had received a brief message from Google stating that their files had been blocked for inappropriate content or failure to comply with Google's terms of service. Many added that they needed to regain access to their files quickly because they were facing deadlines.

Some users also reported the issue on Twitter. Bhaskar Sunkara, founder of the magazine Jacobin, tweeted, "Tfw your finalizing a piece on E. Europe post-socialist parties in Google Drive and Google removes it because it's in violation of its ToS??" National Geographic writer Rachael Bale described similar problems in a series of tweets, noting that she had been locked out of an article about wildlife crime she had been working on.

"I like to use Google Docs for drafts because my editor and I can work together in real time, but this kind of monitoring is creepy," Bale said in one tweet. She added later, "To be clear, I don't think this is targeted censorship. My guess is there's a glitch. Several others have said it just happened to them."

Later in the day, Niemaszyk noted on the Google Docs Help Forum that the issue had been fixed and users could again access their files.

"For more details, this morning, we made a code push that incorrectly flagged a small percentage of Google Docs as abusive, which caused those documents to be automatically blocked," she said. "A fix is in place and all users should have full access to their docs. Protecting users from viruses, malware, and other abusive content is central to user safety. We apologize for the disruption and will put processes in place to prevent this from happening again."

Scanning 'Undermines Online Privacy'

Privacy and civil rights advocates have long expressed their concerns about Google's automated scanning of users' cloud-based content. Google's scanning of Gmail messages for the purpose of serving personalized ads, for example, has been the subject of several lawsuits.

The Electronic Privacy Information Center (EPIC) has led several efforts to stop such practices, and recently filed a friend-of-the-court brief in one case claiming that Google's Gmail scanning violates the Massachusetts Wiretap Act. Another lawsuit prompted Google to stop scanning the emails of education services users in 2014. Such practices "undermined online privacy and prevented the adoption of important security methods, such as end-to-end encryption," according to EPIC.

In June, Google announced that it planned to stop the automated scanning of consumers' Gmail messages to align its practices with those of its G Suite for business users.

"G Suite's Gmail is already not used as input for ads personalization, and Google has decided to follow suit later this year in our free consumer Gmail service," senior vice president of Google Cloud Diane Greene wrote in a blog post. "Consumer Gmail content will not be used or scanned for any ads personalization after this change. This decision brings Gmail ads in line with how we personalize ads for other Google products. Ads shown are based on users’ settings. Users can change those settings at any time, including disabling ads personalization. G Suite will continue to be ad free."