RE: Zappl test, because I couldn't just write a short post on steemit or busy.org, right?

[sircork]

I'd have to go double check, but I am not sure they can filter. I haven't looked closely at the record JSON for a post/comment submission to the block chain, but unless they expressly identify the source app, then no they can't tell where a post was made. They probably do, but it is VERY possible the records dont track this, since they pretty much all have to submit the same JSON to save a record. I could look, but i just woke up and cant be bothered right now :D