It is not my position, in fact it's not even relevant to the issue that's being discussed. The original poster said that "the US will want him to pay taxes on that income and has no way to do so at present", so are therefore making PayPal collect on their behalf by freezing their funds.
My position is that it's not PayPal's role to freeze accounts without the specific guidance of the IRS. It's also not PayPal's business how the individual pays his taxes - he may decide to take the entire amount out of the account and then pay it in cash to the IRS. It's not up to PayPal to freeze the entire sum of money because the IRS wants their cut.