[Jack]

Your Steam might not be connected (In Offline mode) or the Steam servers might be down. Try exiting and rejoining Steam if that doesn't work wait it out, usually resolves it for me.

[Miku]

It means you were banned. For Hacking in your case.

[Empty]

It means you were banned. For Hacking in your case.

I was banned for?

[Miku]

For Hacking in your case.