In the "Permissions" tab under Game Options -> Options, there is a checkbox for "digital" which controls player's access to "digital objects".

The problem is that this includes one of the most dangerous tools to leave public to potentially untrustworthy people: the tablet, as it can be pointed to malicious websites, but also includes relatively harmless but often indispensable tools like counters and calculators, thus turning the checkbox off is not always a viable option.