Cook the pasta in a large saucepan of lightly salted boiling water for 10–12 minutes, or according to the packet instructions, until al dente.
Meanwhile, heat the oil in large frying pan over a moderate heat. Sauté the garlic for 1 minute, then stir in the tomatoes, capers, anchovies and chilli flakes. Cook gently for 10 minutes, stirring from time to time until the sauce thickens slightly, then stir in the olives.
Drain the pasta and tip into a large serving dish. Pour over the sauce and toss to coat well. Sprinkle with parsley and serve immediately.