How utterly self-aggrandizing, disrespectful, and selfish. Their intentions may be to spread awareness of overfishing, but the message that comes through is, "Me-me-me, pay attention to me, I'm a zealot, my beliefs are valid, yours aren't, I'm very important, I could not possibly care less about you and your dining experience this evening."
My husband and I are still in the process of planning our ten year anniversary. If we had happened to make a reservation to celebrate that special night at Nobu and Greenpeace had ruined it, I would have been livid. It's not like we could have returned easily for restitution, given that the nearest location is several states away. What totally rude and inconsiderate behavior.
It is possible to engage in activism without alienating a lot of people in the process. Monterey Bay Aquarium's Seafood Watch pocket guides are a great example, and I do try to order sustainable sushi choices when it is practical to do so. If informed consumers decrease demand for overfished sushi by not buying it, fewer restaurants will carry it because it isn't profitable. Writing a polite letter informing the restaurant of sustainable sushi options and asking them to alter their menu is acceptable as well. Create YouTube videos. Go on talk shows. There are more ways than ever to disseminate information.
However, this is a classically libertarian situation of "Your rights end where my nose begins." Leave the innocent bystanders - the patrons - alone.