Bring a large pot of water to a boil and add macaroni. Cook until al dente, about 8 minutes. Drain and pour into large mixing bowl.

Fry 8 slices of bacon and, when cool enough to handle, crumble into bite sized pieces. Set aside.

Chop tomatoes and green onions, add to small mixing bowl. Mix in mayonnaise and vinegar. Add salt and pepper, to taste.

Pour mayonnaise mixture over macaroni and stir together well. Chill for 2 hours.

Stir in the bacon just before serving. Top with extra green onions, as desired.