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I have gotten two bills since I started tethering -- nothing has changed.

But I'm not abusing it. When I tether I am really just using Wikipedia to look things up and send the occasional email. These are things I could do on my iPhone but are faster on my MacBook and more efficient when I'm studying.

It's not like I'm watching Family Guy episodes off Hulu or HD trailers off Apple.com. My usage has only gone up around ~50 MB a month to 300 MB. I don't think that's going to raise any flags.
 
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