Checked their website
From [link|http://mastercard.com/education/fraud/fraud.html|here]:
Here are some easy steps you can take to protect yourself from fraud.- Sign new cards as soon as you receive them.
It's the very first thing on their list.
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Microsoft offers them the one thing most business people will pay any price for - the ability to say "we had no choice - everyone's doing it that way." -- [link|http://z.iwethey.org/forums/render/content/show?contentid=38978|Andrew Grygus]