The main drawback is that maintains connection logs for network security, which they clearly explain on their website. These logs do not include any browsing or activity, but instead, just basic connection data and everything is erased daily. All support inquiries are handled internally by the network security professionals who run the service (no third-party support).
VPNs are necessary for improving individual privacy, but there are also people for whom a VPN is essential for personal and professional safety. Some journalists and political activists rely on VPN services to circumvent government censorship and safely communicate with the outside world. Check the local laws before using a VPN in China, Russia, Turkey, or any country with with repressive internet policies.

There are lots of good reasons why you need a VPN. The most obvious is that routing your traffic through an encrypted tunnel means it is much harder for people on the same network as you—say, at a coffee shop—to snoop on your activities. If the person who owns the network is a bad guy, spying on your activity and hoping to snatch a password or two, they'll also be foiled by a VPN. This also protects against a lot of other scary scenarios, like DNS poisoning. With that kind of attack, you type in a legitimate website URL but are forwarded to a phishing site designed to steal your information.
Logging Policy – While conducting ExpressVPN review, the privacy policy is one of its strongest aspects. ExpressVPN does not log user data and takes measures to anonymize user-related information that does end in up the systems of the company for technical reasons. The company has clearly stated that they do not log any information that can possibly tell ExpressVPN the purpose for which an individual is using their VPN for. All in all, the logging policy is quite convincingly friendly towards the user.
CHAP is an improvement over PAP because the clear-text password is not sent over the link. Instead, the password is used to create a hash from the original challenge. The server knows the client’s clear-text password and can, therefore, replicate the operation and compare the result to the password sent in the client’s response. CHAP protects against replay attacks by using an arbitrary challenge string for each authentication attempt. CHAP protects against remote-client impersonation by unpredictably sending repeated challenges to the remote client throughout the duration of the connection.
It is also possible (emphasis on "possible") that VPNs may be able to save net neutrality repeal. Kind of. For those who are unaware, net neutrality is the much-discussed concept that ISPs treat web services and apps equally, and not create fast lanes for companies that pay more, or require consumers to sign up for specific plans in order to access services like Netflix or Twitter. Depending on how ISPs respond to a newly deregulated environment, a VPN could tunnel traffic past any choke points or blockades thrown up by ISPs. That said, an obvious response would be to block or throttle all VPN traffic. We'll have to see how this plays out.
Cost: There are two plans here; Premium and Gold, but only the latter supports VPN while the other is just their DNS service. UnoTelly Gold costs $7.95/month if you buy it every month, but there are three other options if you want to purchase it for three months, six months, or one year. Those prices, respectively, are $6.65/month, $6.16/month, and $4.93/month (each, of course, being paid for in one lump sum). You can try it free for eight days through this link.
In this approach, the firewall must be configured with input and output filters on its Internet and perimeter network interfaces to allow the passing of tunnel maintenance traffic and tunneled data to the VPN server. Additional filters can allow the passing of traffic to Web servers, FTP servers, and other types of servers on the perimeter network. As an added layer of security, the VPN server should also be configured with PPTP or L2TP/IPSec packet filters on its perimeter network interface as described in “VPN Server in Front of a Firewall” in this section.
Another reason you might choose to use a VPN is if you have something to hide. This isn't just about folks doing things they shouldn't do. Sometimes people really need to hide information. Take, for example, the person who is worried he or she might be discriminated against by an employer because of a sexual preference or medical condition. Another example is a person who needs to go online but is concerned about revealing location information to a person in their life who might be a threat.

Are you so used to your data traveling over Wi-Fi that you've stopped worrying about the security of that data—and about who else might be spying on it, or even stealing it for nefarious purposes? If so, you are—sadly—in the majority, and you ought to consider using a viritual private network, or VPN. In fact, when PCMag conducted a survey on VPN usage, we found that a dismal 71 percent of the 1,000 respondents had never used a VPN. Even among those who support net neutrality—who you might think would tend to be well informed on technology and privacy issues—only 45 percent had used a VPN.