Man in the Middle

I post to the forum. My internet service provider recognizes my post as BBCode. My internet service provider inserts a spammy link.

If you believe TSL / HTTPS is not always important you are wrong.

Are you sure it's your ISP and not something on your PC?

If it's the ISP, I would change ISP.

The scenario I described is theoretical. (But based on something that happened recently on the forum.)

It is trivial for an ISP to do. It will eventually happen. (Verizon has already done something similar for mobile users.)

If it's the ISP, I would change ISP.

Yup. No more Verizon. (Except when their monopoly leaves me no other choice.)