Using a elite proxy or some other kind of proxy that is completely anonymous means no-one knows what you are doing on the internet, right? Well, the answer to that is kind of yes and kind of no. What you need to look at and understand is how your computer connects to the internet and in turn connects to your proxy server. There are two main steps involved when using any kind of proxy server.
The first is that your home computer must be connected to the internet. Obviously you need to use the service of an ISP that provides customers with home or work internet connections. Once your computer connects to your ISP, you then connect make the direct connection to your proxy server. Here you can see two steps. You first connect to the internet and then you connect to the proxy server. Once you have logged into your proxy you can then begin surfing the internet.
So are you anonymous? Your ISP can see everything you are doing. Since your computer MUST connect to your ISP first, there is really nothing you can do to avoid this. All internet traffic coming to your home computer needs to pass through your ISP connection. So your ISP knows what you are doing, but no-one else. All the websites you visit and everything else you do online is completely anonymous, provided your elite proxies are completely anonymous.
Should you be worried? Is there anything to be concerned about if your ISP can see everything you do while using your proxies? No, I see no reason for anyone to be worried about this. Remember that proxies and everything else you do online needs to comply with local laws, so there is really no need to worry about your ISP seeing that you are using a proxy server.