A telepathy glitch! Not fully blown telepathy, and it wouldn't work over the tablets but any really strong emotions or thoughts in person would be 'read' by those around.

Obviously they'd have to be marked in tags, because obviousness, but... :D Can you really keep your true thoughts hidden? Oh. And they'd have consequences. I'm thinking like the Star Trek: Voyager episode where they craved violent thoughts and then ended up being violent. So whatever those thoughts/feelings were? Those around you might (later) end up acting on them. The stronger the feeling the stronger the need to act them is (you can't stop yourself from doing so either)