service still shaky
Some services let you take phones on vacation, and hackers might decided to trick the system and redirect your calls to them instead.
All kinds of mischief is possible: A rival might try to capture your business sales lead. Or a snoop might listen in on a neighbor's secret calls to a lover.
Though these attacks would be difficult to perform today, security experts believe that as such phones get more popular, hackers will have greater incentive to develop tools for automating such attacks - just as they have with viruses and other computer threats today.
As for reliability, phone providers are still trying to make their systems fully compatible with 911.
In some cases, phones might ring a non-emergency number or fail to provide caller ID details like location - crucial when a caller can't speak.
And during blackouts, traditional phones can draw upon electricity in the phone lines, but an Internet modem will fail without backup power."