You're too lenient. I don't see why allow them to have three attempts. We're adults, stealing is punishable by law, it should not be thought here. One should know from home not to take what is not theirs.
Mute them to have this place clean. Mass adoption will bring a lot of plagiarizers as well, the sooner we send a strong message, the better. This is our home, let's keep it clean!
Thanks for what you're doing here. It is highly appreciated!