Lobbying by technology companies created a revision in model legislation and, as Private Wealth points out in "The Virtual Estate," there is an extremely important difference between the two versions of the legislation.
If you live in a state that has not passed any laws concerning access to a deceased person's digital accounts, then the policies of each company with which you have an account will determine who will have access to them and under what circumstances.
A few states have specific laws on the books, but even those laws vary from state to state. In 2014, the Uniform Law Commission sought to remedy this situation by drafting model legislation for states to pass. More than half the states looked like they were going to pass some version of the legislation. However, technology companies lobbied fiercely against it.
In the original version someone who did not want his or her digital assets to be handled under the law could "opt-out" of it. However, the revised version requires people to specifically "opt-in" to the provisions of the legislation in their wills for their digital assets to be handled under the law. Thus, people without wills would not have their digital assets handled according to the legislation's provisions.
Speak with an estate planning attorney for guidance on handling digital assets in your state.
Reference: Private Wealth (June 17, 2016) "The Virtual Estate"