Developers may share data with third parties so long as they are transparent with the users about how they are using the data.

Google Inc. told lawmakers it continues to allow other companies to scan and share data from Gmail accounts, responding to questions raised on Capitol Hill about privacy and potential misuse of the information contained in users’ emails.

As Google explained in a blog post following the initial story, the kinds of third-party services that it allows to plug into Gmail include email clients, trip planners and customer relationship management systems.

These services, which Google claims to thoroughly vet, typically read emails in an automated way, although humans do sometimes read them too. Users need to actively permit the apps to access their Gmail accounts, and they can revoke permission afterwards.

However, Google’s blog post did not talk about the possibility of those third-party services sharing users’ data with other third parties.