I think it depends on just how much harm your target causing. Sometimes taking them down is the right thing. Doesn't feel justified in this case though.
There are more than two options for a 20 hour wait, and I don't think that lashing out maliciously and staring at water are in my top 100. How about conversation, making friends, reading a book, writing emails, letters, or journals?
Even if we're purely selfish, wasting resources just to stick it to others is not really a productive use of our time.