"Many websites and Facebook pages have been targeted by al-Assad supporters," said US-based Ahed Al Hendi, Arabic programme coordinator for Cyberdissidents.org.
"Many of these comments were death threats and curses and accusations of treason."
In his most recent speech on June 20, Assad spoke of the key role of young people, singling out "the electronic army which has created a real army in a virtual reality."
The Syrian Electronic Army has its own media arm and a Facebook page listing its "latest attacks" by pro-regime hackers.
"They send thousands of reports against the page or profile until Facebook administration shuts it down," said political activist Rami Nakhleh.
The Beirut-based 28-year-old, who goes by the pseudonym Malath Aumran, is part of a growing army of cyber dissidents tapping into social networks to cover events in Syria.
Rights groups say that security forces have killed more than 1,300 civilians and arrested at least 12,000 since anti-government protests began in mid-March.
The Syrian Revolution 2011 -- a Facebook group that has amassed nearly 225,000 "likes" -- has played a vital role in spreading uprising news and videos.
Similar pages have mushroomed to monitor events inside Syria, spread the news and link opposition groups both at home and abroad.
Some "carry out counter attacks against any attempts to hack revolt pages," said Azher, a Syrian online activist who fled to an Arab country in March.
"The electronic army was hacked 26 times" by online dissidents, Azher said.
Assad opponents created the "coalition of Free Syrian Hackers in support of the Syrian revolt," that said it also hacked more than 140 government websites on June 3 alone.
Azher said regime "thugs" post messages on revolt pages "calling for violence and sectarianism" which they then snapshoot and post on their Facebook page as "evidence" of opposition incitement to hatred and violence.
They also post links to articles considered anti-Assad and ask their Facebook fans to comment, resulting in pro-regime mantras.
When asked who is waging the regime's online guerrilla warfare, all three activists who spoke to AFP responded: regime "thugs."
-- 'Thugs by day, thugs by night' --
"The thugs who beat up protesters during the day are the same people recruited to disrupt their online activities at night," Nakhleh said.
Most pages "taking the lead are by people who are close to the Assad regime," said Hendi.
He cited Haidara Suleiman, the son of powerful intelligence officer and current Syrian ambassador in Amman, Bahjat Suleiman.
Suleiman runs the main Bashar al-Assad page on Facebook and is also in the Syrian Electronic Army.
He told AFP that "the official media is unfortunately weak... This is why we use electronic media to show people what's going on."
Asked why Syria bans the international media, Suleiman said: "Journalists refused to enter" the country.
The authorities accuse international satellite channels of exaggerating protests and broadcasting unauthenticated footage.
Damascus's tight grip on information has compelled international media to rely on video clips filmed by the protesters themselves and broadcast on Internet sites such as YouTube.
In an attempt at self-authentication, protesters now carry banners stating the date and neighbourhood where the demonstration is taking place, in addition to taking shots of recognisable local landmarks.
Nakhleh said it can take activists a whole night to upload a two-minute video using a dial-up connection.
"They feel that this is our only weapon against the regime's propaganda machine that fabricates lies against us," he said.
"A young man who goes down to protest while recording footage with his phone is well aware that he will be the first target for any rooftop sniper. When this person goes home, he will certainly not fear uploading this video."
One YouTube video dated July 1 (http://www.youtube.com/watch?v=AXV8F6d0MJY) showed a young man apparently being shot dead after he was caught filming troops opening fire in the flashpoint central city of Homs.
Suleiman dismissed "most of these stories about people getting killed while filming" as "just fairy tales."
"They are going out and protesting daily and no one is doing anything to them," he said.
Nakhleh said Syria's intelligence services "do not have the expertise needed to wage an electronic war" and are helped by their ally Iran.
"I know this from the many emails I receive from people who claim they are Iranian activists. They contact us and send us viruses," Nakhleh said.
He said the Assad regime recruits online agents both to track activists and to hack opposition websites and shut down their Facebook pages.
It is "psychological war," Nakhleh said, with neither side gaining information of strategic value.
"Each side wants to prove that the other side is lying. This is the problem," said Suleiman.
The Internet stealth war may be raging, but for Azher "the real battle is the one taking place on the ground."