someone calling from a recently bought pay as you go mobile?
although they should be able to roughly triangulate position by which phone masts the signal was going through
edit: also caller ID can be turned off. A quick google says you can do this on an iPhone (for example) by hunting through the menus.
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rob, Tue 31 Jul 2012, 16:12,
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That only works when the destination is civilian
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Lord Keeps meaning to procrastinate., Tue 31 Jul 2012, 16:44,
Reply)
I remember prefixing the number you were calling with 191 used to stop giving away your caller ID
dunno if it still works though.
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mr.dogshit The world's premier anthropomorphic canine faeces, Tue 31 Jul 2012, 17:50,
Reply)