Ahh, you guys beat me to it
I had a fresh jar file ready and everything.
Giving out .jar files is also illegal, from what I've heard.
It's not illegal, you are not distributing the whole game, just a part of it.
Minecraft is copyrighted, and the minecraft.jar is part of minecraft. That means you can't redistribute it. There are also custom launchers that just need the .jar files to run it.
Also I'm just merely pointing it out, I don't expect you guys to do anything about it.
EDIT: This is what their policy is by the way The One Major Rule
Do not distribute anything we've made. This includes, but not limited to, the client or the server software for the game. This also includes modified versions of anything we've made. Also, you may not resell any gift codes or licence keys - but of course you can give gift codes as gifts. This is necessary so that we can help stop piracy and fraud - and especially users buying keys that have been fraudulently obtained.
In order to ensure integrity of the game, we need all game downloads to come from a single central source: us. We hope you understand. It's also important for us that 3rd party tools/services don't seem "too official" as we can't guarantee their quality. Make sure to read through our brand guidelines. If you wish to make something pertaining to anything we've made we're humbled, but please make sure that it can't be interpreted as being official. Do not make commercial use of anything we've made unless specifically authorized by us in our brand and assets usage guidelines (which you should read as each of these policies form part of these Terms of Use).