The role of technology in bringing together the protesters has been crucial. The leaders of the protest movement have used community radio stations, mobile-phone messaging and the Internet to forge an identity for lower-income Thais and connect a vast constellation of people in villages and towns.

At times the protests in Bangkok could be described as flash mobs of the disaffected. Protesters, who wear trademark red shirts, have converged on government buildings, banks and military bases across the city guided by text messages.

“This would not have been possible 10 years ago,” said Ms. Thanida, who was returning from military barracks in Bangkok where protesters had demanded that soldiers leave the area. The military acquiesced. Like many protesters, she subscribes to D Station, a “red shirt” news service that gives updates and instructions to protesters.

The leaders of the red-shirted protesters have advertised the current round of protests as class warfare and describe themselves as defenders of the “prai,” a feudal word meaning commoner or lower-class citizen. “The blood of the prai is worth nothing” is a phrase now affixed on bumper stickers and T-shirts.

That may be overblown rhetoric. There are many stories of upward mobility in Thailand and, despite the presence of tens of thousands of protesters, the anger has not translated into personal attacks on the wealthy.

The main target of the protesters’ ire seems to be the system: the perception that bureaucrats and the military serve the elite at the expense of the poor. The protesters bewail the 2006 military coup that removed Thaksin Shinawatra, the tycoon turned prime minister who focused his policies on rural areas. And they question the fairness of a judicial system that removed two subsequent prime ministers who were allied with Mr. Thaksin.

To many outsiders, Mr. Thaksin’s role is puzzling: The notion that a billionaire is leading Thailand’s disaffected to rebellion verges on the absurd. It also infuriates the Bangkok elite, who see Mr. Thaksin’s role as largely self-serving. Mr. Thaksin, most analysts agree, was hardly a paragon of democratic values during his five years in power. He intimidated the media, stripped institutions like the anti-corruption commission of their independence and mixed his business interests with those of the government.