who, the rioters or the authorities?
The rioters, of course.
1.) Counter-narrative; expose rioters as anti-Islam and anti-state as they are breaking both religious and civic responsibilities given the nature of their protest (violent, destroying private property, causing disruption, losses to businesses, looting and plundering, etc.)
2.) Invite the rioting barbarians to explain exactly why, under Islamic principles, they oppose this verdict. They will fail. There is not enough proof to establish a blasphemy conviction. Further exposed.
3.) Invite them to peacefully protest in designated areas and at designated times. This is their right. Blocking highways, destroying property, burning cars, etc., is not. Further exposed when they don't follow this.
4.) Then, when they are sufficiently exposed as nothing but anti-state opportunists, do the operation when they clearly fail to head #3 and other warnings. Focus on arrests rather than indiscriminate use of force.
5.) Prosecute those involved, especially the leaders. Treason wouldn't be a stretch given some of their statements encouraging mutiny and the killing of judges.
We follow this path of hoping things fizzle out every single time. Sure, it avoids short-term chaos but it also emboldens and further empowers these anti-State elements. The message is: you can take over the country any time, destroy property, disrupt lives, etc., and we'll just wait for you to go home. The write of the State has to be established, even if there is short-term violence.