Increased contacts between China and Taiwan present Taiwan with security problems. Security officials say that some 3,000 Chinese agents are in Taiwan at any one time. Since Chinese were allowed to visit Taiwan in the early 1990s, some 67,000 of these agents have visited. Taiwan says it keeps an eye on them as the agents collect information on Taiwan's defenses. Since just observing is not a crime, few of these agents are arrested. More worrisome are the 2,000 Chinese stowaways at large on Taiwan. Some of these could be saboteurs sneaked into Taiwan, to be activated in the event of a war.