We have had this conversation a few times on here before. It goes like this.
I say, "You can't. Once the code is on my computer, I can do with it what I want."
Someone else says, "Oh yes you can, you use an obfuscator. I use <insert name of software here>."
I say, "No, you can't. Browsers can not render obfuscated code, so at some point, it has to be converted to something the browser can read."
Someone says, "Oh yeah, I'll prove it. Give me the code that I used to create <insert web page here>."
I sigh, open Firebug, and return their code to them in about 30 seconds.
Someone says, "Well, I used an old version of <insert name of software here>. The new version works great."
I repeat, "No, it doesn't. Once it is on my computer, I can do with it what I want."
Someone goes away and never comes back.
If you want to protect data, you use Flash, Silverlight, or Java Applets. At least that will make it much harder.
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