Well, due process used in this context normally means innocent until proven guilty. Unfortunately the approach taken in this instance is the reverse 'guilty until proven innocent' or worse 'guilty and that's it'.

Yes, property seizures, arrests, etc. can happen as part of due process however there are complicated legalities associated with those things. For example, you actually need a court order to make an arrest (an arrest warrant) or a warrant to seize property. Getting a court involved means you have to prove something as well, or have enough evidence. Furthermore, other things such as danger to safety, security, flight risk, etc. are all considered by the judge.

I guess that's where due process is being totally skipped here. There is no court order, no warrant, just a threatening letter without any formal basis.