I think an important distinction is:
1. filter based on transaction format
2. vs. filter based on transaction content
format filters are trivial. content filters are difficult.
imho filtering based on content or even intent requires centralizing complexity in filtering, while format based filters are trivial for everyone.
Why do you think that?
I'm sure it would be trivial to create a filter for (say) OFAC-listed addresses. Not materially different from filtering on format.
hm, fair enough.
the point is that anyone can add filters based on format, because simple rules can be used by anyone, no matter how small the miner.
content based filtering needs e.g. content recognition and classification, which can only be pulled of by large miners and puts small ones out of business if that is required, thus centralizing.
you bring up a third case, where e.g. the content based filtering (e.g. ofac) is done by a large third party provider and everyone is required to query them to aplly their derived rules.
still. transaction format is different from transaction content. transaction content is a specific bitcoin address.
its also an uphill battle, because addresses change and folks can make new addresses all the time, unlike bank accounts, where it is harder ...so i think your ofac still falls under content filtering
basically, OFAC would require the ability to filter based on content as well. the process to classify is still impossible by individual miners unless they pull in the classification from big centralized services, so i would recommend ro ensure content based filtering stays unsupported 🙂
