If you check out this page while using Giffgaff data, you'll see that your mobile number has been sent to the website in the header, along with the usual information like browser etc. As far as I can tell this is breach of privacy.
Could someone tell me
-Why O2/Giffgaff do this?
-How I can disable this?
giffgaff staff edit - 25/01 -12:54
We've locked this thread for the time being - not to stop discussion, but because we'd like to update everyone in one place on this.
Please keep an eye on this thread here.
I suspect the short answers are: "because they can" and "no you can't".
It is incredibly sucky. There's always been a need for browsers to reveal some information to the server so that it can render pages correctly, like the IP address of the person requesting the page and their browser type but this really is taking things too far. Hopefully when the word gets out (as it is on Twitter now for example) O2 will stop doing it.
Wow. Sounds like somebody slipped up at O2:
Assuming so I hope and expect it will be rectified urgently.