A secure adjustable mounting system for a tablet computer system in a desired position includes a mount to connect the mounting system to the tablet computer system. A head and post permit articulating movement of the tablet computer. The mount, head, and post collectively may define a passage extending through the mount, head, and post between opposite ends of the passage. The passage is substantially inaccessible from outside the mounting system. In other instances, the mounting system has a first configuration in which the freedom to move the mount relative to the post is limited by a first selectively engageable motion limiter, and a second configuration in which the freedom to move the mount relative to the post is limited by a second selectively engageable motion limiter. The mounting system is further configured so the first and second selectively engageable motion limiters are not accessible from outside the mounting system.