Bummer..... I ran the new GRC Nanoprobe https://nanoprobe.grc.com/x/ne.dll?bh0bkyd2 Showed as 100% stealth...However, the test page also told me that my ISP (Telus in Canada) assigns a 'reverse machine name DNS' to my machine, that appears to be completely independent of changes in my somewhat dynamic IP address.. At the risk of overflowing the page, let me copy an excerpt from Steve's explanation... "Your Internet connection's IP address is uniquely associated with the following "machine name": "ali999cjydfr580h.bc.hsia.telus.net" [altered by moi] The string of text above is known as your Internet connection's "reverse DNS." The end of the string is probably a domain name related to your ISP. This will be common to all customers of this ISP. But the beginning of the string uniquely identifies your Internet connection. The question is: Is the beginning of the string an "account ID" that is uniquely and permanently tied to you, or is it merely related to your current public IP address and thus subject to change? The concern is that any web site can easily retrieve this unique "machine name" (just as we have) whenever you visit. It may be used to uniquely identify you on the Internet. In that way it's like a "supercookie" over which you have no control. You can not disable, delete, or change it. ... ..if the machine name is a fixed account ID assigned by your ISP, as is often the case, then it will follow you and not change when your IP address does change. It can be used to persistently identify you as long as you use this ISP. .......[end of excerpt]. I wanted to check whether this string is 'fixed & unique', so I shut off my modem, and released my IP. I renewed my ADSL modem connection under a completely new IP, went back to GRC, and got exactly the same 'unique machine name' again......At some point I rebooted as well. To my simple mind, forget cookies and IP spoofing and whatever else I may do with Proxo et al, if any and all web sites can uniquely identify this machine ID as long as I continue to use Telus as my ADSL provider..... Any thoughts anyone?