If you believe that the traffic through the ISP is safe enough to protect your data then why do you use https in facebook and gmail? simple http shall do, right?

You have to understand so many attacks including sniffing and tampering of data in order to understand the concept more clear. Read [this][1] to understand why you are recommeneded to use https always.

Coming to the case of VPN, it actually creates an https like connection between the clients who are using the same VPN connecton by encrypting all your data, making your communication in the VPN network secured. [1]: http://mashable.com/2011/05/31/https-web-security/

If you believe that the traffic through the ISP is safe enough to protect your data then why do you use https in facebook and gmail? simple http shall do, right?

You have to understand so many attacks including sniffing and tampering of data in order to understand the concept more clear. Read this to understand why you are recommeneded to use https always.

Coming to the case of VPN, it actually creates an https like connection between the clients who are using the same VPN connecton by encrypting all your data, making your communication in the VPN network secured.