Students in 10 Chicago public high schools can now send police anonymous text messages from their cell phones to alert them of possible violence, and can even earn rewards for doing so. Police say they are taking advantage of the fact that so many students are avid text messengers, and hope that the tips will alert them to possible threats in time to prevent an incident. A Canadian service receives the texts, encrypts them, and resends the messages to local police without their originating phone numbers. Students can call a toll-free number to see if their tip resulted in an arrest. An arrest for murder, for example, can bring a reward of up to $1,000. Sept. 9, http://www.suntimes.com.