Ridiculous.
All this means eg. Signal would not be able to escape jurisdictions, because no bank anywhere relevant will endanger their SWIFT access opposing the US. Sanctioned Signal would stop providing services for everyone, since they can't pay for servers, neither being able to receive donations, nor wire any money themselves. It's similar prior situations involving payment processors (e.g. in case of Wikileaks), but has totalitarian reach affecting almost all banking globally.
In this example, Signal itself and anyone associated with it, could not have any bank accounts at all. There wouldn't be any receiving end for donations. Being on the OFAC list means any bank connected through SWIFT wouldn't allow you as customer. Current funds would be immediately frozen, which by itself would probably cause fatal disruption. The OFAC list is an extreme measure, which is why the recent abuse is such a big deal.
As mentioned elsewhere, read up on the Rote Hilfe case to see how this kinda thing plays out right now. "Antifa Ost", four people beating up (NOT murdering) Neonazis were declared a designated global terror network by the Trump admin in 2025. Those four "global terrorist" were all already in custody, on trial in Germany at the time, hardly a threat. Rote Hilfe lost their bank account, because of weak association through legal defense support. Mind you, Rote Hilfe is a traditional German political institution being only cancelled once before: 1933. And the GLS bank who cancelled their account proactively fearing SWIFT exclusion, would be considered a socialist endeavor by US standards. That's the reach of OFAC.
So, to evade sanctions, Signal would need to maintain internationally ostracized money laundering networks on the scale of global terror financing, or North Korean operations. They are not some hidden service black market, where any hosting is sufficient. Paying AWS millions for large scale, low-latency CDN infrastructure with highly suspicious finances ain't gonna fly. I assume, due to statistic correlation, considering the necessary volumes moved, it's probably simply impossible to pull off.
And of course, Signal's income is in large parts coming from various nation's registered funds, which obviously wouldn't participate in highly illegal financing. Individual donations won't cut it (and also expose any donor to being flagged for terror financing, losing access to their own accounts). Not to mention, money laundering infrastructure isn't free, so only a fraction of donations would make it anyway...
The problem here is also Signal's centralized nature. If it was built for a decentralized, self-hostable backend, where only the code itself has to escape repression, it wouldn't be as vulnerable. However, as with other decentralized projects, we likely wouldn't talk about it as hypothetical heavy loss due to wide-spread adoption and foundation of common privacy.
Signal's whole mission is to enable e2ee at scale, for the average person. OFAC listing would be the end of Signal and any similar project.
Not really, unless exchanges don't let you withdraw coins into your own wallet? It's trivial for someone to buy another coin like BTC/ETH then use it to purchase Monero via defi.