Originally Posted by drofgnal
Short answer is yes, they can be if the plane's electronics were not specifically designed to handle it (cable shielding, etc.) Ever put a blackberry next to a speaker phone and listen (radiated suspectiblity). Now imagine a pilot trying to listen to the tower doing critical final manuevering to landing during an IFR approach.
Ultimately, the airlines are too cheap to take the obvious answer, as are the airports themselves. Most towers (at least as of 2003, when I read some articles on this issue) are still using 1950s equipment instead of modern, more efficient GPS systems.