Childishness aside, this is a dumb idea because it's going to piss off more users than appease. Most don't care about the struggle for internet freedom or whatever, and just want their sites to work. For them blocking legitimate sites a sign that their ISP is broken, especially when their friends/colleges report that it's working fine on their connections. Moreover blocking illegal streaming sites is court sanctioned whereas blocking the plaintiff's sites is not, and likely expose them to getting sued for tortious interference or similar.
I'm not sure how that's any less childish/tortious interference. At the end of the day you're still unilaterally deciding to interfere with some company's website.
