|Along those lines, the US NRC issued an Information Notice IN97-82
|documenting an inadvertent initiation of a Halon fire suppression system
|caused by a camera flash affecting an uncovered EPROM - a copy can be found
|on the NRC web site.

Many types of IC's will experience operational malfunction if
exposed to bright light, even if none of the light reaches into
the UV spectrum (e.g. a normal focused incandescent can cause
problems).  Although the required amount of light is higher than
would be ambient in normal circumstances, it's not all that great.

>From what I can tell, the light has two effects: [1] Memory cells
may fail to read as programmed even when they are, resulting in
errant program execution.  The overprogramming margin used will
probably affect a chip's light succeptibility (a really geeky
hacker could butn some MOVLW instructions with the operand bits
weakly programmed and use a PIC as a lightmeter!); [2] The amount
of current drawn by the PIC will increase with light intensity.
In most cases, the current draw increase will be negligible, but
devices which are to run for a long time from a battery should
probably have their window covered.