SAN JOSE, Calif. (AP) — Chinese President Xi Jinping and American counterpart Barack Obama will talk cyber-security this week in California, but experts say the state’s Silicon Valley and its signature high-tech firms should provide the front lines in the increasingly aggressive fight against overseas hackers.

With China seeking to grow its economy and expand its technology base, companies like Facebook, Apple, Google and Twitter are inviting targets. In fact, all have been attacked and all point the finger at China, which has denied any role.