[kator]

Just checked my Verizon 4G LTE MiFi and the headers are not there, I've not done anything special to my account settings.

On ATT I see the X-Acr thing but not clear if it's UID like or not in nature, would need to see more of them.

[13throwaway]

I just checked my AT&T phone and I have an X-Acr header too.

[wittymebee1]

Just checked my phone and I have "do not track" turned on and x-acr is tracking. Who/what is it? Why? How do I stop it?

[tehwebguy]

Same, I've opted out here and I still get it:

http://www.att.com/gen/privacy-policy?pid=24339

[wittymebee1]

Checked over data not WiFi

[kngspook]

How're you checking?

[13throwaway]

Go to this page over a cellular connection. (Turn off your wifi) http://checkyourinfo.com/request Then look for a long number.

[kator]

Checked my Wife's Verizon iPad on LTE and no UID header.