In December, a number of Iranian nationals inside the U.S. and in other countries reported being barred from the communication software Slack in an apparent bid to comply with U.S. sanctions. As a result, the National Iranian American Council sent a letter on December 20 to Slack leadership seeking clarification and warning that over-enforcement of sanctions causes substantial harm and can be seen as a form of discrimination.

On December 22, Slack responded to NIAC, stating that “Slack users, including users of Iranian descent residing outside of Iran, had their accounts deactivated in error this week. Our system for applying geolocation information relies on IP addresses, and in the process of updating that system, accounts tied to embargoed countries were deactivated.” Slack apologized for implementing its blocks poorly and indicated that it would evaluate its procedures for maintaining sanctions compliance.

NIAC will continue to monitor companies’ efforts to comply with sanctions with an eye toward impacts on Iranian Americans and Iranian nationals in the United States.

The full letter from Slack is below: