The online community rallied on Thursday in support of live protests against the U.S. government's surveillance of internet activity, a practice recently exposed by a former contractor for the National Security Agency.
Websites such as Reddit and Mozilla supported a campaign in cities across the United States to "Restore the Fourth" - a reference to the U.S. Constitution's Fourth Amendment, which protects citizens against unlawful search and seizure.
The home page of the website Boing Boing, for example, displayed the following message to the NSA: "Happy 4th of July! Immediately stop your unconstitutional spying on the world's internet users -- The People."
The protest comes as the United States celebrates its Independence Day holiday.
By early afternoon, crowds of more than 400 had gathered in New York City and Washington, D.C., the organizers said. They estimate the total turnout will be more than 10,000 nationwide.
The NSA, on its own website, said: "NSA does not object to any lawful, peaceful protest. NSA and its employees work diligently and lawfully every day, around the clock, to protect the nation and its people."
Former NSA contractor Edward Snowden has been charged with espionage after disclosing the agency's surveillance programs. He has spent more than a week in a Moscow airport seeking a country that would grant him asylum.
The online protest was launched by the Internet Defense League, a network of more than 30,000 websites and internet users whose goal is to protest attempts to curtail the freedom of the Web.
Evan Greer, a spokesman for the IDL, said nearly 13,500 Twitter users had taken part in a so-called thunderclap, in which they all tweeted the same or similar message at the same time to their more than 9 million followers.
Sentences for cyber crime and snooping to be tougher across EU
EU lawmakers agreed on Thursday to toughen criminal penalties across the European Union for cyber attacks, especially those that include harming critical national infrastructure and hijacking computers to steal sensitive data.
The 28 EU member states currently have a patchwork of varying tariffs for cyber crime.
The decision mandates national maximum sentences of at least two years in prison for attempting to illegally access information systems.
The maximum penalty for attacks against infrastructure such as power plants, transport, or government networks will be set at five years or more, higher than the current tariff in most member states.
The decision also increases the penalties for illegally intercepting communications, or producing and selling tools to do this.
Cyber criminals often infect computers to form armies of zombie PCs known as "botnets" by sending spam emails containing malicious links and attachments, and by infecting legitimate websites with computer viruses.
Some botnet creators rent or sell infected machines on underground markets to other cyber criminals looking to engage in a wide variety of activities including credit card theft and attacks on government websites.
In June, Microsoft helped to break up one of the world's largest cyber crime botnets, believed to have stolen more than $500 million from bank accounts.
Under the new EU rules, companies that benefit from botnets or hire hackers to steal secrets will be liable for any offences committed on their behalf.
The European Parliament in Strasbourg voted 541 to 91 with nine abstentions on the proposal by the European Commission, the EU executive. However, Denmark has chosen to opt out of the rules, wanting to keep its own system in place.
EU governments now have two years to translate the decision into national law.
UK teams with defence and telecom companies on cyber security
Nine of the world's biggest weapon makers and telecoms providers are teaming up with Britain to bolster the country's cyber security, aiming to tackle the increasing threat of hacking and other such attacks.
Britain made cyber security one of its top national defence priorities in 2010, citing the growing menace of digital attacks from criminals and state-sponsored overseas groups.
BAE Systems, Rolls-Royce, Lockheed Martin and Hewlett Packard are among companies that will team up with government to share information on tackling cyber threats, the Ministry of Defence said on Friday.
The country's government and industry networks suffer from about 70 sophisticated cyber attacks a month, with 15 per cent of that against the defence sector, said GCHQ, the government spy centre which is also involved in the scheme.
The partnership also comes as contractors such as BAE build up their cyber businesses in anticipation of rising demand from governments and companies, at a time when demand for equipment suffers in defence budget cuts.
The so-called Defence Cyber Protection Partnership will look to implement controls and share threat intelligence to increase the security of the defence supply chain.
"This is a clear demonstration that government and industry can work together - sharing information, experience and expertise" said Minister for Defence Equipment, Support and Technology Philip Dunne.
Other companies in the partnership are Finmeccanica's Selex unit, EADS's Cassidian arm, Thales, CGI Group and BT Group Plc.