You can't really be sued for fixing Smartphones.
What it does is it voids the Smartphone's return/ fix policy, where the company does not accept it for any repair if it breaks regardless of how much money you're willing to pay. It's the same deal with Rooting your Smartphone.
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Anyways... Ringo... I get this feeling that even tho Tsukasa is being kind to Ringo, he's still just using her most of the times for her talent. Because we already know Tsukasa is a type of Politician that plans for his best benefits.