Using the cheaper unlimited plan worked for a long time, and then AT&T started 'automatically' switching people to the smartphone tax if their IMEI indicated they had an android phone. I did what any reasonable person would do, cancelled my AT&T contract and signed up with t-mobile :-)
http://modmyi.com/forums/iphone-news/755094-t-cracking-down-...
I use TetherMe ($2 in the cydia store, instead of $10 for mywi, enables native tethering), and I haven't gotten this message.
There are people on that thread showing they used 10+GB/month, connecting their Xbox 360s to Live via their phones, etc. That certainly seems like a way to get "noticed" by AT&T.
edit: one guy on there pasted his usage from AT&T's account manager - 165 GB!
I use the Tethering on my Nexus One (Tmobile) from time to time, but I don't abuse it. I use it as an emergency backup internet access for cases like if the wifi at the hotel isn't working, etc. IMHO, that's reasonable and my usage when tethered probably isn't much more than when I run things like Pandora or Youtube on my phone.
If I were using 10+G/month, then I'd expect to have to pay for a higher priced "tethering included" plan.
I've yet to be switched away from my $10/mo data plan.
I was using an HTC TyTn2 that I didn't purchase at a Cingular Store and I was on the $15 data plan. Never got caught with this phone, probably because they didn't know what phone to map my IMEI to.
I got a Nexus One for AT&T last year, and received an auto upgrade SMS shortly after, saying that my Nexus One required another plan...
I have paid £x to use O2's (or in this case AT&T's) network, not only that but I also had to partially pay for the handset.
O2 should not really give a damn about what device I use to access their network - sure, they may have sold me a handset with an Internet plan, but it is MY DECISION to use whatever device I see fit to use that network.
If I am allowed to use whatever device I want but it was capped to say 4GB, I would have no issue, but as it stands, I am not only paying to use the phone, but an additional bullshit cost to tether the phone which technically should be none of their concern.
There's no underlying issue. You accepted their offer of a subsidized handset in exchange for entering into a contract to buy voice & data for that handset, or an equivalent, for a period of time. Your agreement pertains to that type of device only, clearly stated in the T&C's.
Now, if you want to argue that tethering charges to use your bandwidth is a dick move, or that mobile operators should NOT be able to discriminate, or charge more just because you own a certain device, then I completely agree. But neither of those are what you agreed to.
To slightly modify your airline analogy, this is like going on a business trip and flying economy. The airline scans your baggage, notices that you have packed your suit and other work-related items and demands that you pay the business class fare. "Hold on a minute," you complain, "I am entitled to 20kg of hold baggage and 7kg of hand baggage, so long as it fits with certain dimensions and isn't dangerous!" The airline retort: "Read the small print. Business travellers with certain items in their baggage will be charge the business class fare, which will be charged to your credit card. Now, enjoy the flight and don't forget to pay attention to the safety announcement."
EDIT Removed the '(Ars)' from the title. N00b mistake :)
[1] http://www.reddit.com/r/technology/comments/g62wv/i_woke_up_...
Requesting non-mobile versions of sites that do not have the option
User Agent strings such as "Internet Explorer" or "Safari" in HTTP requests
Sending screen sizes via relatively common web calls
The use of UA-Pixels at all, especially when specifying large screen sizes.
Use of protocols that are only seen in desktop OS programs (ventrilo, starcraft2, etc for instance is one that should be a good detector).
Honestly, any respectable nerd is going to have either a) a box to SSH to or b) a VPN endpoint... if you encrypt/encapsulate all traffic originating from your tethered machine there's very little chance they'd be able to catch you.
Also, what's about if I setup permanent openvpn connection from the phone to some dedicated server?
