2. I bet you more than anything that this person wan't to decompile a swf just so he can say he can. Or show his friends how he gave himself 900 lives in some game. Either way, its harmless and a learning experience that gives knowledge of how things run down at low levels. This brings me to my next point.
3. Something is not always right or wrong just because it is legal or illegal respectively. It is not illegal for me to take apart my computer, or any other device for that matter, and it is most certainly not wrong. Its common. When a big company comes out with something new, rival compaines buy of some of those devices and dissect them to see how they did it. Same goes for software. If it is not wrong for me to take apart my compter, it is not wrong for me to take apart someones software. As long as I don't redistribute it, or do anything that hurts the developer with it (for instance, distributing or "opening up" the source) there is nothing I am doing wrong. Whether it is illegal or not, it is still not "wrong" to decompile software if your intentions are good.
4. Seeing as this topic contains content that can be used with perfectly good intent, it should not be removed, as it would be a violation of freedom. I commend the mods for that.
5. All this being said, do punish the people who want to learn, punish the people who are actually doing the wrong things, like redistributing source and infringing on other people's copyrights/patents/etc. Because as long as the world exists there will always be those of us that call themselves hackers, the ones who want to take apart, try new things, learn everything there is to know about something from the bottom up, attempt to use things for purposes never thought or for purposes that things were never meant to be used. We push the limit, and we do it "because we can."
i think i've tried all decompilers on the net and choose Flash Decompiler Trillix (most of all cause it works with flash cs4 better then others). now i'm thinking about purchasing it, but may be someone can advise better one.
Shame on him if he is trying to decompile and pass off someone else's work as his own, but, the completely legitimate reason that brings me here asking the same question is:
The client I'm currently working for has some flash on the webpage and the original creators have gone out of business. That leaves me no option (other than recreating it from scratch). Imagine trying to guess the site where they pulled the stock photography from.
Also, if you're working for a client and they paid you for your work, it's no longer your work to protect. It's called "work for hire." Once they pay you, it's theirs. Unless your work agreement specifically states that you retain all rights to every single bit of the media, it's the client's.