Foreign leaders have welcomed US President Barack Obama's announcement on plans to curb the National Security Authority's powers. US agencies will only use bulk collection of data to fight terrorism, protect troops and allies, and combat crime.
The European Commission has said Barack Obama's reforms to the National Security Agency are important steps towards rebuilding trust between the US and the EU.
President Obama has ordered curbs on practices by US intelligence agencies, promising to end the surveillance of world leaders and officials.
"Trust in EU-US data flows has been affected by revelations on these intelligence programmes and needs to be rebuilt. In recognising the need for action, President Obama has taken important steps towards rebuilding that trust," a statement from the European Commission read.
The existence of the US intelligence programme that allegedly monitored the phone of Germany's chancellor Angela Merkel concerned EU leaders.
A legal adviser to Edward Snowden said that Barack Obama's swipe at the US intelligence leaker in his speech on Friday was "unnecessary" and framed the privacy issue in a false way of making people choose between liberty and security.
Jesselyn Radack, the national security and human rights director at the Government Accountability Project, said: "His unnecessary swipe at Snowden for the unauthorized disclosure ... was really unwarranted."
President Obama unveiled NSA reforms during a long-awaited speech that balanced pledges to increase privacy protections with a warning that intelligence gathering would continue.
President Obama's "acknowledgement of the need for a full and public debate" has been welcomed by shadow foreign secretary Douglas Alexander.
Mr Alexander said that is no longer enough for oversight to be used as a reason by security services.
The very fact that President Obama has examined these issues is evidence that a debate is already under way in the US. So it is understandable that people here in the UK will welcome similar discussions of these issues.
Whilst of course the legal, accountability, and representative structures in the US are different from those that we have here in Britain, there is a need for a wider debate here in the UK about what ongoing reforms could be put in place to uphold effective oversight and accountability.
The debate on spying has only just begun, said Guardian journalist Glenn Greenwald who published the revelations of NSA whistleblower Edward Snowden.
Responding to reforms on surveillance announced by President Obama today, Mr Greenwald told Channel 4 News: "There are some changes, some which are substantive such as putting an actual advocate in the Fisa court so not only the government is heard from.
"I think the problem is the fundamental nature of the NSA that has created worldwide controversy namely spying on people by the hundreds of millions without suspicion, will continue to endure".
President Obama's speech on security and privacy reforms were "embarrassing", Wikileaks founder Julian Assange has said.
Mr Assange, who has been inside the Ecuadorian Embassy in London for more than a year to avoid extradition to the US told CNN: "I think it's embarrassing for a head of state to go on for 45 minutes and say almost nothing.
"It's clear that the president would not be speaking here today if it were not for the actions of Edward Snowden and whistleblowers before him...these whistleblowers have forced this debate. This president has been dragged kicking and screaming to today's address", he added.
"Unfortunately today we also see very few concrete reforms".
This was the long awaited speech by the President on the limits of data collection and intelligence gathering. Of course, prompted by the spectacular leaks by the NSA contractor Edward Snowden.
The President made no apology for US spying, but he acknowledges that there has been a breach of privacy and in trust. So he made promises to America's friends and allies around the world.
I think it is fair to say that somewhere in Russia or wherever he is hiding, Snowden himself will see this as something of a personal victory for it is crystal clear that this speech and this national debate that is going on across America would not be happening without Snowden's intervention.
The British Government has been urged to follow Barack Obama's example in increasing the oversight and accountability of intelligence agencies.
Nick Pickles, the director of privacy campaigners Big Brother Watch, said that Britain was "lagging behind" the US in terms of surveillance.
President Obama recognised public debate had been insufficient and that law has failed to keep pace with technological change. Both of these issues are more pronounced in Britain, but go unaddressed by the agencies.
President Obama emphasised the need for judicial oversight by courts, greater transparency by the Government and companies and for the legal basis of surveillance programmes to be public. All of these issues should be pursued in Britain to protect our privacy and our economy.
President Obama has announced reforms to US surveillance programmes, which would include new rules for the use of National Security Letters, forcing companies to provide information to the government without informing the subject of the investigation.
Under the plans, the reforms include:
A series of "concrete and substantial" reforms that the administration seeks to pursue with Congress.
Additional restrictions are to be placed on the government’s ability to retain, search, and use in criminal cases, communications between American and foreign citizens.
Amend how National Security Letters are used.
Mr Obama has asked the Director of National Intelligence, in consultation with the Attorney General, to annually review any future opinions of the secret intelligence court and report to him on these efforts.
The President also ordered a transition that will end the bulk metadata programme as it currently exists, and find a way for the government to avoid holding this data.
US intelligence will continue to gather information about the intentions of other governments, and will not apologise simply because US spy services are more effective, President Obama said as he announced reforms to US surveillance programmes.
Mr Obama warned that "we cannot unilaterally disarm our intelligence agencies." He added, "We know that the intelligence services of other countries - including some who feign surprise over the Snowden disclosures - are constantly probing our government and private sector networks."
But he said the US must be held to a higher standard. "No one expects China to have an open debate about their surveillance programmes, or Russia to take the privacy concerns of citizens into account."
President Obama has said "there is a reason" why Blackberries and smart phones are not allowed in the White House situation room, during a conference addressing reforms to the National Security Agency's intelligence gathering.
Mr Obama noted that many of the countries who have loudly protested against American surveillance programmes themselves seek intelligence on the US.