Hey BishopB,
I agree that other technologies are more safer, but Flash is the only file format with mass popularity that cannot have its source viewed into. An SWF file has no intelligble (is that a word?) content for any hacker or such.
While ActionScript viewer can easily see the actions you have in a movie, you can add a arcane line of code that prevents a program from sniffing a SWF file. upuaut8’s answer might be solution to issues many people had with Flash and security.