It disappoints me that somebody would do this bullshit on a server Giygas is kind enough to let us play on. As a previous server admin, I'll explain how this can make it even rougher on him/her.
Okay, so yes there are plugins that can log block breaks, item frames, and chests. But here's the catch. Most, if not all of them, require a MySQL library. Most server hosts charge you extra for MySQL, and it is NOT easy to setup. So whoever is doing this, you could end up costing Giygas actual money as well as even more free time setting this shit up just to catch you. Which is a real d-baggy thing to do and I hope you feel like the dick you are.