Founded and best known as an organization employing nonviolent struggle as a course of action against the Milošević-controlled Serbian authorities, Otpor grew into a civic youth movement whose activity culminated on 5 October 2000 with Milošević's overthrow.

[2] After the overthrow, Otpor launched campaigns to hold the new government accountable, pressing for democratic reforms and fighting corruption, as well as insisting on cooperation with the International Criminal Tribunal (ICTY) at the Hague.

Otpor was formed in Belgrade on 10 October 1998 in response to a controversial piece of legislation in Serbia – the university law – introduced earlier that year by the Serbian government under Prime Minister Mirko Marjanović.

[11] In his explanation of the sentence, judge Željko Muniža cited that "with their brazen and reckless behaviour, the four students have endangered the citizens' calm and disturbed the public order."

[13] The organization gained further prominence when the Dnevni telegraf (daily tabloid owned and edited by Slavko Ćuruvija) 7 November issue appeared on newsstands with Otpor's ad featuring the clenched fist symbol on the front page.

Seeing the Otpor ad on the front page, the authorities quickly reacted again, taking Ćuruvija and his collaborators to court within days via a trumped up private citizen's complaint and handing them another draconian fine under the information law, this time prompting the newspaper's relocation to Podgorica.

It stressed the importance of mobilizing the population to vote, but also promoted "individual resistance" (i.e. nonviolent methods of civic disobedience in order to counter possible electoral fraud).

By aiming their activities at the pool of youth abstainers and other disillusioned voters, Otpor contributed to one of the biggest turnouts ever for the 24 September 2000 federal presidential elections with more than 4,77 million votes (72% of the total electorate).

Milošević had in the past succeeded in persuading the public that his political opponents were traitors working for foreign interests, but in the case of Otpor, the tactic largely backfired, as the beatings and imprisonments of their members during the summer of 2000 only further cemented the decision to vote against the government in many voters' minds.

[21] It used the following ten strategies to achieve success: Humor was the basis of Otpor's campaigns; it used irony to provoke the government and motivate Serbians to join the movement.

Back home a couple of days later, FR Yugoslavia's foreign minister Goran Svilanović held a reception for Otpor's delegation consisting of Milja Jovanović, Ivan Andrić, and Nenad Konstantinović in order to congratulate them on the MTV award.

Otpor initially attempted to establish itself in a "watch dog" role after the revolution by launching campaigns holding the new government accountable, pressing for democratic reforms, and fighting corruption.

[39][40] Contacting various officials from the U.S. based organizations, in his New York Times Magazine piece, journalist Roger Cohen sought to shed some light on the extent of American logistical and financial assistance received by Otpor.

[39] Just how much of the US resources appropriated in the year 2000 by USAID, for democracy and governance, which included support to groups that worked to bring an end to the Milošević era through peaceful, democratic means, went to Otpor is not clear.

[44] In addition to former Otpor activists such as Slobodan Homen, Nenad Konstantinović, Ivan Marović, Predrag Lečić, Stanko Lazendić, and Srđan Milivojević, the candidate list featured established professionals in other arenas such as professor and anti-corruption campaigner Čedomir Čupić, political analyst Dušan Janjić, psychologist Žarko Trebješanin, lawyer Boža Pelević, and former Serbian Supreme Court vice-president Zoran Ivošević.

By spring 2004, in the aftermath of the election, the organization faced more turmoil when Branimir Nikolić, a prominent activist from Otpor's Subotica chapter, publicly accused the party central, namely Homen and Konstantinović, of embezzlement.

[54] Former activists Srđa Popović, Slobodan Đinović, Slobodan Homen, Nenad Konstantinović, Dejan Ranđić, Ivan Andrić, Andreja Stamenković, Milja Jovanović, Branko Ilić, Srđan Milivojević, Jovan Ratković, Predrag Lečić, Vlada Pavlov, Stanko Lazendić, Miloš Gagić, and Siniša Šikman were on hand at the presidential palace at Andrićev Venac,[55] giving Tadić an old Otpor poster.

[57] The next day, in Stari dvor, the exhibition of Otpor's materials was opened with Belgrade mayor Dragan Đilas saluting the former movement for "the courage shown in the fight for democratic changes and thus enabling others to live in a normal country".

[63][64][65][66][67][68][69][70][71][72][73] Shortly after 5 October 2000 revolution, he left Otpor to pursue a political career in Serbia, becoming a Democratic Party (DS) MP in the Serbian assembly as well as an environmental adviser to prime minister Zoran Đinđić.

Simultaneous to his political engagement, Popović, together with former colleagues from Otpor Predrag Lečić and Andreja Stamenković, founded the environmental non-governmental organization Green Fist.

In 2003, Popović, with another prominent former Otpor member Slobodan Đinović, co-founded Centre for Applied Non Violent Actions and Strategies, (CANVAS), an organization focused on the use of nonviolent conflict to promote human rights and democracy, and eventually quit actively participating in Serbian politics.

Popović additionally heads the Ecotopia fund,[83] the non-profit organization dealing with the environmental issues, financially backed by various Serbian governmental institutions as well as the private sector.

In November 2011, Foreign Policy Magazine listed Srdja Popovic as one of the "Top 100 Global Thinkers" of 2011 for inspiring the Arab Spring protesters directly and indirectly and educating activists about nonviolent social change in the Middle East.

Described by sources quoted in the Serbian media[11] as Otpor's "alpha and omega" during the movement's heyday in the spring and summer of 2000, Homen and his cousin Nenad Konstantinović handled everything from money to transportation.

Some accused Homen of an obvious conflict of interest in this situation after allegations appeared that his family actually rented out the space to Otpor, which was paying for it with the money from the incoming donations.

Following the 10 October 2010 mass rioting by the right-wing groups in protest of the Belgrade gay pride parade, standing in front of the Democratic Party headquarters that were attacked by the rioters, Homen went on state-television airwaves, delivering a threatening message to the "hooligans".

[97] During his Otpor days, Slobodan Đinović, leader of the student organization at the University of Belgrade's Faculty of Mechanical Engineering,[98] founded an NGO called the Center for Political Analysis (CPA).

[101] In the documentary film The Revolution Business produced by Austrian TV ORF and distributed by Journeyman Pictures, Srdja Popović claimed Đinović is the main financial backer of CANVAS.

After the revolution, he left the movement for politics, joining the Civic Alliance of Serbia (GSS) and becoming managing board member of the state-owned Belgrade Youth Center.

There were several award-winning documentaries made about the movement, most notably Making of The Revolution by Eric Van Den Broek and Katarina Rejger (launched at the Amnesty International Film Festival in 2001) and Bringing Down A Dictator by Steve York, which won a Peabody Award in 2002, narrated by Martin Sheen.