(If this is already implemented, I couldn't find the option!)
A lot of scammers are sending fraudulent/phishing links in SMSes/text messages nowadays.
I tested 3 links and all of them worked - I was not alerted or prevented from visiting them, so naturally I wanted to report them as deceptive sites.
On desktop Firefox, you can report a site as deceptive:
I would like a way of reporting bad sites for mobile too, so it can help others avoid these scams.