Why is it safe to use copy & paste in Flash but not in Javascript?

I'm trying to use copy'n paste in one of my web apps and have read a few articles/SO qu开发者_如何转开发estions about it. Most people say that using Flash is the only option since most browsers don't allow access to the system clipboard because of security concerns.

I can understand this but I wonder why it is okay for Flash do this, but not for the browser.

Or has it got nothing to do with security and it is simply to complicated to implement this for cross-platform browser vendors?

Its generally not "ok" for Flash to do this for the same exact reasons that the majority of browser vendors disallow it. Adobe runs in their own world however, and there is little anyone can do about it.