The rise of the group now called the Islamic State as an armed force controlling substantial territory started well before the Arab Spring, and is a pretty direct result of the US invasion and occupation of Iraq, and particular policy choices made during that occupation.

Admittedly, then it was just called the "Islamic State in Iraq". If you want to blame the Arab Spring for contributing the situation in which occasioned its next two name changes and its expansion into Syria, sure, but if it hadn't felt secure enough in Iraq to form separate groups to go fight in Syria rather than worrying about holding on to its (at the time) core territory, it couldn't have exploited that opportunity.

The sectarian corrupt violent syrian state and the U.S. invasion of Irak are much better suspects

No, the Islamic State in Iraq, which arose in Iraq before the Arab Spring, became the Islamic State in Iraq and the Levant (and later simply the Islamic State) after sending offshoots to fight in the Syrian Civil War, and then reintegrating those offshoots. But it is a mistake to say that the Syrian Civil War "became" IS; before the Arab Spring and Syrian Civil War, the Islamic State in Iraq was already a substantial armed force holding territory and heavy weapons, most of which were taken from the Iraqi military, which it became as it grew up fueled largely by resistance to the US occupation (and, for a while, its temporary attachment to the al-Qaeda brand as "al-Qaeda in Iraq", which was useful when al-Qaeda was the most visible brand in Islamist opposition to the U.S., though eventually they outgrew the need to be a franchise of a foreign brand.)

do you see a lot of difference between Iran's revolution and Arab Spring?

>The sectarian corrupt violent syrian state and the U.S. invasion of Irak are much better suspects

Granted similar elements - a major group of population dissatisfied with the governing power as well as US hand cooperating with the side/power opposing to that group - were present in Iran too. One can see how religious extremists hijack that dissatisfaction and use US' involvement to fuel it. So the US' involvement is a catalyst, not the root cause.

If anything, Facebook and Twitter kept a lid on things. Only when the governments cut the national net connections did things really hit the fan.

This likely because now people had to actually go out and talk to their neighbors to figure out what was happening, and thus were more easily pulled along.