To improve the security of your account, as well as to prevent spam, abuse, and other violations of our Terms of Service, we may collect metadata such as your IP address, devices and Telegram apps you've used, history of username changes, etc. If collected, this metadata can be kept for 12 months maximum.
We’ve designed the Signal service to minimize the data we retain about Signal users, so the only information we can produce in response to a request like this is the date and time a user registered with Signal and the last date of a user’s connectivity to the Signal service.