The guy is bitching so much in the thread, claiming that he's been profiled based on his race (and not the fact that he connected to Slack from Iran at some point), that it's hard to take him seriously.
It’s pretty clear that’s it not motivated by race or any kind of profiling.
Slack has no incentive to boot more people off their platform than necessary, so this overly broad ban could be a result of either misunderstanding the US governments mandate, or that might be just what they were asked to do.
The mundane includes things like contracting with the Federal government or even certain government contractors. Our company just contracted with PAE, and PAE contractors must agree to much of the same Federal Acquisition Regulations as someone doing business directly with the Federal government. One of the vendor forms was 37 pages long, and it contains sections explicitly requiring certifications that your company will comply with sanctions. The form binds the signer to personal culpability for failure.
So if you're a company contracting in this process you're tasked with preventing delivery of your product to Iran, and the Federal government gets to set the bar, not you. If you fail to meet the bar, you end up in Michael Flynn's shoes, only far less public. How long of a bet is it to expect a Federal bureaucrat will interpret compliance the same way you do? Are you willing to risk inquiry if your opinions differ?
I don't like what's happening here. I don't like it at all, but I know just enough about dealing with the Federal government that I can smell the odor from here.
It sounds as though you have access to data that the rest of people on HN do not. Would you care to share your source? Are you certain he would not have been banned by Slack if he were not an Iran citizen (just Canadian) but would have (possibly) used Slack when travelling to Iran?
We're both adults here and I assume we both can realize that splitting these hairs doesn't make my statement that banning everyone that's ever logged on Iran from slack is, in effect, a ban on Iranian ethnic users?
So no, a ban based on signing in from a specific locale has zero to do with ethnicity or race.
On the other, the author of the thread is accusing Slack of profiling him racially. What he's implying is that a human proceeded to stalk him around the Internet, on social networks, etc to check if he is an actual Iranian and ban him based on that. And that is a very, very grave accusation.
Banning anyone who has ever used Farsi in Slack, now that would be a bit closer to banning for ethnicity.