Cognos, a software company ravaged by the Melissa virus, configured its mail servers to block incoming e-mail attachments exceeding 25KB.

CNN: Protect yourself from the next Melissa

For starters, you've got to be on EV-DO or WiFi, because 1xRTT (in addition to being ridiculously slow) would block incoming calls when active.

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Jammers also block incoming calls, which means that if used for an extended period you prevent anyone in your vicinity from hearing pressing, even emergency, news.

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