I see people say that NordVPN is a bad choice all the time, but I've never seen any credible evidence that they're not trustworthy. Can anyone provide any sources with valid reasons to avoid their service? I only know that they had some servers hacked in 2018, but it seems as though they took that very seriously and upgraded their hardware and encryption accordingly. I'm just trying to decide if I want to start looking at alternatives, but honestly I'm pretty satisfied with my experience so far.
As others have said, my biggest problem with NordVPN is the dishonest ads. Other big commercial VPN providers are guilty of it, too. A VPN provides very little in the way of security. Tom Scott has a pretty good break down of the problem with VPN ads.
I also object to their pricing. They push you to commit to a 1-2 year contract. If you have a good reason to use a VPN often (like bypassing geographic restrictions) then maybe it makes sense. For me, I rarely need it. If I do want to use a VPN, I can get 30 days with Mullvad for 5 euro without signing up for a year+ commitment.
ProtonVPN, one of the most recommended VPNs that I can find, also pushes you toward a 1-2 year contract. Mullvad is probably the only one that doesn't (and they just removed port forwarding).