The protest was due to economic hardship from the sanctions, https://www.iranintl.com/en/202601200029

> “President Trump ordered the Treasury and our OFAC division to put maximum pressure on Iran and it worked,” US Treasury Secretary Scott Bessent said when asked whether US sanctions on Iran were effective.

> In December their economy collapsed. We saw a major bank go under. The central bank has started to print money. There is a dollar shortage. They are not able to get imports and this is why the people took to the street,” he added.

And incited by Mossad, https://www.jpost.com/middle-east/iran-news/article-881733

> “Go out together into the streets. The time has come,” the Mossad wrote.

> It continued, “We are with you. Not only from a distance and verbally. We are with you in the field.”

> The statement was a rare open acknowledgment from the Mossad regarding ongoing operations in Iran.

It was obviously a regime-change operation by US and Israel.