The Lebanese have had no shortage of things to protest in recent years, with a barren economy that forces many young people to leave the country for good jobs, with landfills and beaches overflowing with trash and with the government perpetually deadlocked over reforms. But the last month has brought more than its usual share of indignities: a faltering currency, crises over wheat and gas and, earlier this week, forest fires for which the government was so unprepared that it was forced to turn to its neighbors for firefighting help.

On Thursday evening, the government announced a tax on calls made using popular internet messaging services including WhatsApp, Facebook Messenger and FaceTime, a measure it said would help raise revenue amid a fiscal crisis. For many Lebanese, who already pay some of the highest mobile service rates in the region — there are only two telecom companies in the country, both state-owned — this was going too far.

“For 30 years, we’ve been living in this same corrupt system, and now there’s not even money left for them to steal anymore,” said Semaan Khawami, 45, an artist who was handing out small Lebanese flags to protesters on motorbikes in downtown Beirut on Friday morning. “So now they’re coming up with new ways to steal from us.”

By day’s end, most of the country’s political leaders had weighed in, to little effect, with some even urging their followers to demonstrate against the government. Prime Minister Saad Hariri, meanwhile, delivered a televised speech acknowledging the “suffering” of the Lebanese, insisting that he had done his best to solve the crisis, and giving all factions in the government a 72-hour deadline to enact fiscal reforms that would unlock $11 billion in international donor funds. (The tax on messaging services also was retracted.)

The economic crisis and the flagging value of the Lebanese pound mean that “ordinary citizens will see their pensions disappear, their standards of living plummet and the future of their children in jeopardy,” Maha Yahya, the director of the Beirut-based Carnegie Middle East Center, wrote on Twitter, predicting that the protesters would persist until Mr. Hariri and his national unity government resigned.