All messaging applications have support for link previews, this feature expands any website links you send or receive in a chat with images and any brief description. A recent study has shown that these previews can leak all your sensitive data, drain your battery and consume bandwidth.
To preview, you have to visit the link through the app, open the file that’s in there and survey it. This can leave you vulnerable to malware or force an app to download files that are too big, causing it to crash and drain the battery.
Surprisingly, the list of apps included messengers from Facebook, Instagram, LinkedIn, Line and few others. Some cases of these apps were found with issues such as leaking IP addresses, unnecessarily downloading gigabytes of data in background and exposing links sent in end to end encrypted chats.
Facebook Messenger and Instagram showed the worst results as they would download a copy of a linked file in its entirety, even if it was gigabytes in size. Most other apps would cap the amount of data anywhere from 15MB to 50MB.
These findings are quite alarming; your personal information isn’t safe on any online platform. Private messages are not so private.