I think the snake oil claim is in regard to VPN companies marketing themselves as a security product. The security benefits that these companies claim in their ads are dubious but of course there’s other benefits to them, they just can’t advertise that they can be used for these things.

The problem is people who aren’t aware of this see these ads and think that they actually do prevent hackers from stealing their information.

> I think the snake oil claim is in regard to VPN companies marketing themselves as a security product

Considering that confidentiality is a vital component of overall security, it's not necessarily unreasonable to describe a VPN as a security product. Of course, it's not the panacea some companies claim; nobody's "surfing the web in full security and privacy" with just a VPN service.

We already have really good client-server confidentiality (and integrity) assurances from the wide adoption of TLS/HTTPS. Wrapping that in a VPN doesn't buy you all that much additional security. Maybe a little bit of DNS privacy and being able to mask your IP address on torrents, but that's all that comes to mind.

That argument only makes sense if people don't really understand what a VPN is or what it is actually for. They're somewhat of an expensive and complex thing that usually noticeably slows down your internet connection... I doubt many people are buying them because they think it protects them from identity theft or something. I haven't seen an ad on the internet in a decade (thanks uBlock) - so I'm not sure if there's some ubiquitous misleading ads I'm missing.