"Death to the dictator, Ahmadi[nejad] is a liar, the government of coup d'état…should resign...should resign," he wrote, in a set of rhyming, rhythmic slogans in Persian.
On Tuesday night Ahmadinejad addressed the Iranian nation on television, blaming the protest casualties on foreign powers accused of meddling in the country's election. The rooftop chants could be heard around Tehran during his broadcast.
Monday's meeting of opposition leaders endorsed the subtler forms of resistance, without calling for supporters to protest in the streets. Iranian authorities have again threatened to prosecute opposition leaders, including Mousavi, criminalizing most forms of protests including blogs and communication with foreign news channels.
The government is fighting back.
"The daily growth of anti-regime satellite channels and ... websites needs serious measures to confront this phenomenon," read a circular issued this weekend by Ayatollah Mahmoud Hashemi-Shahroudi, the head of Iran's judiciary.
Detainees released from state custody have described brutal physical and sexual abuse, including hours in stress positions and days under bright lights. One detainee said he was waterboarded using hot water and a towel.
As their stories emerge they reinforce through fear the state's security hold on the country.
"It feels like martial law," said Beheshteh, 26, an opposition supporter in Tehran.
"There are checkpoints, they randomly pull over cars…so you're on edge because its not a normal – the forces are everywhere."
Over the weekend the Association of Researchers and Teachers of Qom, a prominent pro-reform clerical organization in the Shiite holy city, criticized Ahmedinejad's reelection and the state's violent response to opposition protests. For Iran's theocratic government it was a bold statement, rebuking the Guardian Council, Iran's highest judicial body heavily influenced by Supreme Leader Ayatollah Ali Khamenei.
Analysts say the election hasn't created divisions in Iran's theocratic government; rather, it has hardened them.
"The regime knows it is in minority in Qom," said Dr. Ali Ansari. "The problem hasn't been to find clerics who disagree with what's happened. It's finding those people who are willing to say it."
What may be more significant than what pro-reform clerics have said is what conservative clerics haven't. Many have refrained from congratulating Ahmedinejad; in withholding that blessing they signal their reservations about a process publicly endorsed be the Supreme Leader himself.
"The major clerical groups' silence and the Association's public dissent suggest real discontent among clerics, which if activated could further delegitimize an already weakened regime," wrote Cliff Kupchan of the Eurasia Group.
"Loss of clerical support would make the government even more reliant on its guns. Force may be enough to ensure regime survival - but survival of a government with a very narrow support base."