Here's an article from 2010 saying they hadn't given a single ticket in Boston or Cambridge in years. To my knowledge they still don't give out the tickets. I've certainly jaywalked in front of cops in Boston, Cambridge, Somerville, and Quincy without penalty for decades. So even if it's in the state law it's not enforced around Boston.

I lived in the Seattle area for a couple years and that's the only time in my life I ever saw a person penalized for jaywalking and I was shocked to see it. One of the reasons I'm glad to be back in Boston.