These seemingly independent VPNs are all connected – and they pose a threat to your data

An academic study has revealed hidden links between a number of VPNs, with apps sharing ownership and even security flaws.

These apps can in no way be considered some of the best VPNs, but they are popular. The combined Google Play Store downloads of them exceed 900 million.

Earlier this year, we reported on VPNs having links to the Chinese military. Investigations were carried out by the Tech Transparency Project (TTP) and this study builds upon the TTP's work.

Many apps uncovered by the TTP appear in the new study and can be grouped into "families" – sharing developers, code, and vulnerabilities.

Many of these VPNs are free or have free versions. Here at Tom's Guide, we always recommend subscribing to a paid VPN over a free one. You get more features, faster speeds, and an all-around