How safe is using FON hotspots?

This is probably a noob question, but how safe is using FON hotspots?
I know it's probably not a good idea to check my bank account, or do anything envolving money transactions, when I'm on FON hotspots, or any other open access WiFi, by the way. But other than that, should I avoid using FON for the other day to day stuff? I don't mean checking the weather or reading the news... I'm talking about something more like checking emails, logging in to forums, logging in to webhosts, etc... As long as it's an https connection, am I secure? Or should I always use a VPN when on a WiFi hotspot(FON or not)?
Are free VPN any good? I think I know the answer to that one, but anyway I would like to hear from you on this, as there might be some exceptions.
What if I'm using an android device, should I also be worried about security and use a VPN?
I know that many of you believe that one should always use a VPN, even when using my home connection, but at this moment my main objective is to find out if it's secure to use a FON hotspot, and how can I make its usage more secure. When accessing FON using my PC, I usually use a virtual machine running Ubuntu, but from time to time I also use it while running windows. Is running windows riskier?

Thanks in advance.

Can anyone shed some light on this?

What is FON ???

Fon is a Global WiFi Network.
Fon members share a bit of their home WiFi, and in turn get free access at millions of other Fon hotspots worldwide.

Always use a VPN when using a public WiFi network.
You can buy a $10 exploit to jack public traffic.
Never trust the guy using his laptop at the railway station he
could be sniffing.

I was surprised to find out that a local hotspot scans SSL traffic as well. The thing performs MITM and can fake SSL certs and scan within packets of encrypted data. So any password sent will be cleartext to them.

Don`t ever trust public networks, not even your own wi-fi is safe as has been reported recently in the media they can scan all your traffic from hundreds of yards away.

oxonbeef said:

Always use a VPN when using a public WiFi network.
You can buy a $10 exploit to jack public traffic.
Never trust the guy using his laptop at the railway station he
could be sniffing.

Click to expand...

So I guess that being kind of paranoid is the best way to keep safe...

bartosimpsonio said:

I was surprised to find out that a local hotspot scans SSL traffic as well. The thing performs MITM and can fake SSL certs and scan within packets of encrypted data. So any password sent will be cleartext to them.
Don`t ever trust public networks, not even your own wi-fi is safe as has been reported recently in the media they can scan all your traffic from hundreds of yards away.

Click to expand...

But as Oxonbeef said I'm secure if I use a VPN, right?
Can you recommend a good VPN for using with android?