Following news that students at a Los Angeles high school had hacked district-issued iPads and were using them for personal use, district officials have halted home use of the Apple tablets until further notice. It took exactly one week for nearly 300 students at Theodore Roosevelt High School to hack through security so they could surf the Web on their new school-issued iPads, raising new concerns about a plan to distribute the devices to all students in the district. “Outside of the district’s network … a user is free to download content and applications and browse the Internet without restriction,” two senior administrators said in a memo to the Board of education and L.A. schools Supt. John Deasy. “As student safety is of paramount concern, breach of the … system must not occur.”