Comparing popular VPNs? Folks on Reddit have some thoughts.

The bottom line is simple: People don't want other people watching what they're doing online, even if they're not doing anything wrong.

A VPN (virtual private network) is an internet security subscription that basically allows you to make up your own internet rules. It acts as a bodyguard between you and your internet service provider (and hackers and other third-party weirdos) by hollowing out a personal anonymity tunnel through which you perform all of your internet activities. A VPN's job is to plug the holes that could be making your data vulnerable to nefarious eyeballs, like creeps scouring public WiFi networks for personal information that could be used to steal your identity. VPNs are as wise of a precaution as antivirus software or a password manager (yes, this applies to Macs too).

Hackers love free WiFi for the same reason you do: Connecting to the internet requires no authentication. That network is littered with unsecured devices, many times belonging to working professionals with bank accounts and business credentials that have phishers frothing at the mouth.

Often, the easiest thing for hackers to do is slide in between your device and the connection point. This Man-in-the-Middle situation is like eavesdropping, but on emails, credit card info, and work logins. Other hackers use public WiFi to unleash malware to all of the suckers using the network without protection.

The specs that Reddit users care about in a VPN are easy to tally when the same ones (or multiple people bitching about the lack of the same feature) pop up in countless subreddits throughout the year. If you're not feeling hardcore enough to build your own VPN, like some users suggest, here are the frequently-mentioned points that Reddit suggests to look for:

Streaming dependability is a given. Tons of people want a VPN solely to watch content from other countries, so a VPN's ability to fake out geoblocks and get around a streaming site's VPN blocks is crucial. (If you, in the U.S. want to watch a Netflix show that's only available in France, you'd want to pick a VPN with a plethora of servers in France.)

The speed at which that content streams matters, too (a fast VPN should be able to upscale to HD without lag). Connection speed and location spoofing are dependent on the number of servers and where they're located — more servers mean fewer people hogging a single server's capacity, and various locations mean more streaming libraries from around the world. (Free VPNs typically don't have the funds to support as robust of a menu of servers.)

For obvious reasons, most big streaming services aren't psyched about the idea of VPN usage and will probably mention it in their terms and conditions. If they happen to sniff out your VPN-ridden IP address, you're not necessarily screwed. The most likely repercussions would be the inability to access the streaming platform (even if it just worked the day before), but there have been instances of steaming services terminating subscriptions associated with spoofing.

Split tunneling can aid with traffic jams as well. VPNs that support split tunneling let you route some of your traffic through the encrypted VPN tunnel while bouncing other traffic over the internet directly. One might choose to separate less demanding but high-security activities like web browsing from high-bandwidth but low-security activities like streaming or playing video games. Advantages include reduced traffic on corporate networks, better speeds and reduced latency for the chosen tasks, and more customized privacy. If you're looking to tunnel to specific apps, look for an SSL VPN.

No DNS leaking is a good test of a VPN's trustworthiness. Think of a DNS (Domain Name Service) as the internet's phonebook: It's the service that transfers host names for humans to understand (like Mashable.com) to IP addresses for computers to understand. A leaked DNS essentially blabs your browsing history to whoever's watching on the other end — thus totally defeating the purpose of a VPN.

A kill switch cuts your connection to the internet if a secure connection to your VPN drops without notice. This is less likely on a high-quality VPN with a hefty roster of servers that can balance the traffic of millions of users, but far from impossible. By default, your device will switch back to your personal IP address or, worse, a public one. The speedy end-all action performed by a kill switch essentially ensures that you aren't unknowingly operating on a weak IP address. Some kill switches operate in the form of a firewall.

Jurisdiction — or the country in which a VPN is originally based — will dictate the privacy laws that VPN has to follow. Some places are nosier than others, mostly depending on their membership in an intelligence-sharing alliance (or not): The Five Eyes, Nine Eyes, and Fourteen Eyes are all but guaranteed to come up in any subreddit about a certain VPN's privacy policy. Countries in these groups have agreements related to third-party sharing and may be following strict data retention laws, depending on their legal jurisdiction. (Let's say a VPN is officially based in the U.S. but has an office in Switzerland. The company can decide to follow Swiss legal obligations in order to avoid loopholes that make user data vulnerable.)

App compatibility can make or break your VPN experience.Before signing up, make sure that your chosen VPN's app doesn't have major bugs on your operating system. For instance, some mobile VPN apps don't play as well on iPhone as Android, or an app might keep getting killed depending on other apps sucking your phone's battery. Alternatively, if you're using a VPN to stream on your TV, ensure that the service has a dedicated TV app.

Unblocking streaming services is probably the most universally useful feature of VPNs, even for casual internet users who don't think twice about eyes on their browsing habits. All decent VPNs offer a wide selection of servers based in multiple geographic locations. Picking one of those essentially tricks your ISP into thinking your device is based there, maneuvering around geoblocks and opening the door to another country's Netflix library or BBC iPlayer. American fans of the UEFA Champions League or Love Island UK could also use location spoofing to watch a live game or episode.

If you know to check Reddit for VPN advice, you likely already have some general knowledge about VPN protocols. But here's a breakdown if you need a refresher: A protocol is the rulebook that dictates how the VPN client talks to the VPN server and creates a tunnel, ultimately playing a role in security and vulnerabilities. Two modern protocols often come up in conversation on Reddit among users who don't want to use their VPN's native client: Wireguard and OpenVPN.

Both are open source, giving anyone in the community access to the source code to conduct their own investigation on potential security flaws — and Reddit users appreciate the ability to take things into their own hands. Wireguard's simpler code base is a little easier to crack and offers technical perks like better encryption and connection times, but it's not as polished as OpenVPN. OpenVPN, on the other hand, is the go-to for streamers and gamers.