Pretty much standard stuff and well known. You only need coins on the exchange if you trade. If you're holding then put it away man, that's common sense. But anyways it's good to have this kind of topics so people can read and do something about it. Nobody's gonna hack your phone because you're irrelevant but many hackers were trying for years to for example hack PS4 and they did it in the end.  Everything is hackable it just depends how big of a target it is.