I'll address the Linux issue in a way you will understand.

Linux can't (natively) run code written for Windows. It is probably due to this that you heard this comment, where a new virus is spreading through e-mail and Linux isn't effected. If you download a EXE file off of a website that is for Windows, then Linux won't be able to run it, and will simply ask you what you want to open the file with. It is like an unknown type of file. This is why if you want to buy games for Linux, you need to make sure you get a Linux version of the game since the Windows version simply won't work. Linux can sort of act like Windows with a program called WINE. That program reads an EXE for Windows and can usually run it in Linux by changing some functions or libraries around when the Windows EXE asks for them.

In short, there is code that can hurt Linux, but it has to be written specifically for Linux. Chances are that you won't find a virus for Linux spreading through the Internet/E-mail since few people run Linux, and all of the people who run Windows, their PC wouldn't know what to do with the Linux Binary Executable so it wouldn't spread through them. Very few people would be affected and many people (running Windows) will just end up with files that "don't work" in their e-mail, and go on to run attachments in all of the other e-mails in their Junk Mail folder and cause some *real* damage... Unfortunately they would probably also think that the file that "didn't work" caused the problem, and not the ones that did infact work...


And sorry I don't have a link..., but I think my explanation is pretty valid (first paragraph). The second paragraph happens to be my speculation into the situation...


*edit:
It can't be serious, lol. IIRC, the binary system was in use well before that, in calculators and stuff. Funny, I've never seen that before.