Interesting. My default with issues like this is to assume that this is localized to you. Thus far, no one else seems to be experiencing the same issues, so I'm leaning pretty heavily in that direction. We do a lot to ensure the safety and security of our users, so I'm even more confident that this isn't our (my team's) fault.
But! The script you highlight, from Casale Media, is curious to me. Casale Media is Index Exchange, the company we use to manage our programmatic offerings. My assumption is that script is unrelated to your issue, and the fact that it appears only in Firefox is just the way the source code is displayed is different there versus Chrome.
As I state above: my current assumption is that this is an issue local to you. That said, I'm in the process of communicating with our contacts at both our ad server, Adzerk, and our programmatic partner, Index Exchange, to confirm that script is functioning as it should. I'll provide any relevant updates here.
Thank you for bringing this to our attention!
Update: our contact at Index Exchange confirmed that the script is only used for user-matching to ensure impressions are correctly delivered to who is targeted (ie: a user in France or a user visiting the .net tag). No content is delivered via this script. I hope this helps!