Place the corn in a large pot with enough water to cover, and bring to a boil. Cook until kernels are tender but crisp, about 5 minutes. Drain, and cool in cold water. Use a knife to scrape kernels from the cobs.
Place kernels in a medium bowl. Stir in avocados, red onion, bell pepper, and garlic. Add cumin, red pepper flakes, and cilantro. Mix in vinegar, olive oil, and lime juice. Season with salt and pepper.