Quote from retaildaytrader:
Here is the other benefit that I forgot to mention. By using one of these services, any internet data that goes between your laptop and the proxy server is encrypted. You are basically on a VPN. There are always ways around encryption, but you would need the equipment and to know what you are doing to break it which means 99.9% of everyone out there would not be able to look at what you are doing.
When would this be important? For example, lets say you travel a lot and use public wi-fi. Lets say you use your personal computer at work over their lines. These services would stop man in the middle attacks.
Lets say you handle a lot of sensitive transactions involving large amounts of money over your computer then a VPN setup is absolutely essential.
I have not used the services you mentioned but from the little I know about computing it seems to me that in order for them to work with IE they have to disable DEP, something that puts you in a highly risky position because you depend on them to filter the bad content.
I once heard that a person using one of these services managed to hide his identity but ended up formatting his hard drive.