I spent 2 hours on T-mobile's tech support line and the folks over in India don't seem to be able to comprehend this issue. T-mobile eventually transferred me to Apple (?!?) who said it was T-mobile's problem and I should talk to them. I'm kind of at a loss as to where to go with this now. Phone: Iphone 5s 7.0.4 Browser: Mercury Browser Plan: Tmobile unlimited data $30/month without the $15/month hotspot option Issue: Mercury Browser is by far my favorite browser, it blows Safari away right now, though maybe Safari will improve with 7.1. Mercury allows changing the "user agent" in settings, to for example "IE 8" or "Firefox 23" which is really nice because then almost all web sites will send me the regular version of their page, rather than a typically brain dead mobile version. The problem is that T-mobile's system is picking this up as Tethering/Hotspot usage and now I keep getting directed to T-mobile's web page telling me to pay $15 for the tethering option. I didn't notice this before because the system waits for 100Mb of tethering usage before directing to that page. If I switch back to a "mobile" user agent, everything works again but then I'm stuck viewing braindead mobile web sites. Just changing the user agent in a mobile browser is NOT tethering so T-mobile's system needs to come up with a better way of detecting tethering usage. I emailed the Mercury developer but haven't heard back. T-mobile's tech support people have no idea what I'm talking about. Any suggestions besides paying them $15/month extra for what I should be getting anyway?