In most states, there are very specific laws dealing with the abandonment on intangible property, such as money in accounts, stocks and bonds, travelers cheques, etc.

And all that I have heard of, the intangible property can't ever be claimed by the holder. A number of states have specifically enacted the Uniform Unclaimed Property Act of 1995, and those that haven't either are likely still using either the Uniform Disposition of Unclaimed Property Act of 1954 or the Uniform Unclaimed Property Act of 1981, or their own regulations significantly based on them.

Instead, for money in accounts of any type, after 5 years (used to be 7) without the owner claiming it, it is considered officially unclaimed.
It then MUST be turned over to the custody of the unclaimed property division of the owner's state, if the owner's state can not be determined, then it is turned over to the custody of the holder's state, to be held for the owner to make claims of at any point in the future.

I believe you can turn the property over to the appropriate division of government before that period, if holding it is something that would impose upon you.

At no point is it yours, and your spending, withdrawing, or in any manner using any of it, for any reason can get you into legal trouble.