My understanding is the only account seized was MtGox's (well technically their US subsidiary). It was MtGox funds in MtGox account which were seized. No user should have had any funds seized.
Really? My understanding of what happened is different. Remember, as an ordinary user to move any funds from USD to MtGox account USD took a bit of delay via Dwolla, even if your Dwolla funds were clear. In reverse the process was similar. When withdrawing USD from MtGox it would take maybe a day for that to credit to your Dwolla account (it used to be 2 weeks or more). At any given time I imagine many thousands of dollars in limbo given the size of MtGox. So if you had a pending transaction during the freeze operation I would think funds were stuck.
That's just my understanding of it.
Yes but the funds in "limbo" would be MtGox. Funds technically are never in limbo. Banks work on atomic transactions. At no point is a dollar in both account nor is it in neither account. Companies may impose delays related to various procedures or limits on cashflow but a dollar is either in MtGox account (which becomes an asset of MtGox) or in a customer's account (which wasn't seized).
My point is DHS didn't seize any accounts except MtGox US bank account and Dwolla account, those funds are the assets of MtGox. MtGox has a corresponding liability of the amount owed customers such that prior to the seizure the net is $0.00 (i.e. $xx,xxxx assets in MtGox funding accounts, -$xx,xxx owed to clients). The loss of the asset doesn't erase the liability. i.e. MTGox lost $xx,xxx but they still owe customers $xx,xxxx. MtGox could simply credit any transaction in progress back to the client's MtGox account and write the loss off (temporary if they win in court) against retained profits. Luckily for clients MtGox has been very profitable.
So it is my hunch (total outsider opinion) that MtGox just "ate" the total amount of seized funds (as they should).
If any customer lost funds over this they have been suspiciously silent for a long time, which lets be honest NEVER happens on bitcointalk. 
