Despite their no-logs claims, most VPN providers do keep at least some logs. Their intentions behind data storage can differ tremendously, though, and that's exactly what makes a difference between a trustworthy VPN provider and a not-so-trustworthy one. VPN providers that are genuinely respectful of your privacy (like those above) only store the essential information which is necessary for the improvement of their services, and which, in no way, can be related to a user. Less reliable VPN services, on the other hand, usually collect all sorts of personal data, which not only can be used to identify a person but also for black market data trafficking and financial gain.