My listing and the listings of three of my competitors were hijacked on Wed. The hijacker was trying to engage in arbitrage and put little boxes under the title with quantities in each box. Clicking on a box took the customer to the hijacker's page where one could buy my product for 4x my price.
Remedy: I went to the customer service email on seller central where there's a category for violations. I submitted my email and within 24 hours my listing was restored. I still had to call SC and talk to someone in catalog to restore my title. I see my competitors' titles have not yet been restored. (Trying to edit the title myself didn't work.)
I hope this helps anyone who needs it!