I read Vizio TVs run Linux/systemd, after this lawsuit concludes, you should be able to get the source code and reinstall Linux at least.
Any tips and pointers would be much appreciated, in terms of common ways to search for and exploit vulnerabilities, or the exploitation of other televisions. Alternatively, if this is an absolute fool's errand, and the whole thing is locked down tighter than Fort Knox, a firm warning that this is not a good thing to dick around with over a weekend would also be appreciated.