Todaygold,
If your american you may have more to worry about than shell companies
for 2016, the estate and gift tax exemption is $5.45 million per individual, up from $5.43 million in 2015. That means an individual can leave $5.45 million to heirs and pay no federal estate or gift tax. A married couple will be able to shield $10.9 million from federal estate and gift taxes.
14 states also have inheritance tax on top. The rate varies.
deez007 is absolutely correct if you have assets that could be taxable above the limits then at the very least a Trust or a Trust that "owns" a corp or LLC is appropriate for domain holdings. Trusts/Corps/LLC's are subject to different tax rates as I'm sure you know
that could lower the effective tax on assets. This is why trusts/corps are used. Nothing illegal at all.
Domains held for a long time would be treated as capital assets regardless of how they are held. When it matters is when they are
sold and what tax rate the heir might be subject to based on their current income and state they live in. Any solid business person worth their salt would address the issue prior to death for the maximum benefit of the lowest tax rate on the assets to their heirs. There is nothing illegal about using every possible tax rule to minimize tax.
Another reason to do this now is - If a person gets sued for any reason if the domains are not "held" in a separate entity they are subject to attachment for any judgment that may be levied against them. If one has a portfolio of any size or value if one ends up in bankruptcy, again one would be forced to sell often at wholesale to make other creditors whole.
If they are in a trust or established corp. then the suit or bankruptcy can't touch them.
This is how Trump has retained 100's of millions in assets while going thru many bankruptcies.
It is also common practice for real property flippers and landlords to hold each property in it's own corp. to "shield" it from any potential liability from the other properties. The same goes for corporations. They own separate corps. for the same reasons.
Recent example : Google creating a "Holding" corp. abc.xyz
Please don't bother with a rebuttal. Regardless of what anyone posts on forums like this, each person has the responsibility to do their own research to know what is actually truth. And I would guess the only concern for you at this time would be State inheritance tax issues.
Cheers