Firefox for J2ME would mean Mozilla would have to run a server containing a specialized Gecko renderer that outputs a simplified form of the page as simple markup, plus a J2ME client that would finish rendering from the simplified output. Great concept but too many problems.
How do you figure that? There is nothing saying that you have to do it the way Opera Mini et al are doing it. Of course you can implement a complete web browser in J2ME (it might however not be practical depending on the specifications of the target devices).
Why should this be any different from what research scientists do all the time (with actual security holes to boot)? Just write up a research paper (or a blog post or whatever) and describe the problem and give some thoughts to possible solutions (user not being mindless idiots anymore) and release it. There is definitely nothing ethically wrong with it in my book (and there shouldn't be in anyone else's either).
Here in Sweden a blogger (without any income from the blog at all) got the verdict that blogging is an occupation and therefore he must either quit blogging or loose his unemployment check.
http://www.dn.se/nyheter/sverige/arbetslos-bloggare-kraver-besked-om-a-kassa-1.842969
Hackers of the world, unite!