I believe Three have a clause for their handset data add-on that prohibits use a modem, but I've never heard of it being enforced. Might be worth checking the T&C's.
Not sure, perhaps by looking at such things as the User-Agent field within HTTP request headers?The question is how could they find out exactly ? If can only cap your usage, how quickly you hit that cap is no consequence to them.
They can identify modem use easily because the computer will dial *99# on the phone to start a new data connection.
Does that happen if you connection share over wi-fi?
They can identify modem use easily because the computer will dial *99# on the phone to start a new data connection.

Hi
My tariff with Vodafone allows me to have unlimited use of the internet with my handset(n95 8gb)
But does it cover when connected to a pc to make a net connection? Or will I be charged accordingly?
Thanks.
I've got the 3 X-series package and hardly use any data, what do people use mobile internet for?
I occasionally use Fring, check email and surf, but only use around 20mb a month.
Work emails via Push, i easily use 100s a month downloading attachments etc