DO YOU HAVE a Yahoo email account? If so, you should close it.

Why? Because Yahoo was just caught with their hand in the cookie jar, it appears.

An explosive story by Reuters describes how in 2015, Yahoo searched the emails of all its users and made them available to the US government.

The search was done in real time, when the emails were received by those who have a Yahoo account.

There are still grey areas and unclear issues at this stage, but if the story is accurate, it constitutes the latest instance of a “big brother” government expanding its surveillance powers to yet a higher degree.

What happened is that the FBI and the National Security Agency told Yahoo they were investigating a terrorist organisation’s communications, and since that organisation used Yahoo email, all Yahoo users’ emails had to be scanned.

The messages were searched for “selectors”, which means specific email addresses, phone numbers or other keywords.

Sometimes, such intelligence gathering is targeted at foreigners, but this time it seems that literally every single person who has a Yahoo email inbox was placed under surveillance, all citizens included.

It looks bad for Yahoo, which claims, “We fight any requests that we deem unclear, improper, over-broad, or unlawful… We’ve worked hard over the years to earn our users’ trust and we fight hard to preserve it.”

The main problem, of course, is that sweeping searches go against the principle that we should not be subject to unreasonable searches, as the Electronic Frontier Foundation put it.

The American Civil Liberties Union (ACLU) was spot on when it stated:

Based on this report, the order issued to Yahoo appears to be unprecedented and unconstitutional. The government appears to have compelled Yahoo to conduct precisely the type of general, suspicionless search that the Fourth Amendment was intended to prohibit. It is deeply disappointing that Yahoo declined to challenge this sweeping surveillance order, because customers are counting on technology companies to stand up to novel spying demands in court.

It also comes as another blow to US government efforts to pretend that all is well and that big internet companies are respecting our privacy.

For example, in 2013, Obama tried to be reassuring by claiming that the “NSA is not rifling through ordinary people’s emails” and that surveillance was only “a circumscribed, narrow system”.

What happened with Yahoo shows that the opposite is the case.

The good news is that, according to the latest information, Yahoo is the only company to have received the order and it is not scanning emails in that way anymore.

On the other hand, there have been many other programmes allowing the US intelligence community to spy on our communications.

This has been most clearly revealed by Edward Snowden, the former intelligence company employee.

AP / Press Association Images AP / Press Association Images / Press Association Images

Here is a list of some of the many secret programmes he helped uncover (the codenames could be coming straight out of detective novels): Gilgamesh, Anticrisis Girl, Victorydance, Captivatedaudience, Royal Concierge, Mystic.

The story of how he leaked documents to the world has now been made into a movie entitled Snowden, which for some reason doesn’t yet have a release date in Ireland, although it does in many other countries.

For example, one of those secret programmes is called PRISM, about which there has been a good number of news stories. Starting in 2007, it gave the National Security Agency direct access to the servers of Google, Skype, Apple, Facebook and other internet giants.

Government officials have thus been able to collect information such as the content of emails, live chats, search histories, and more.

Because the companies involved are the main providers of online communication services, one can appreciate the size of the programme.

Another programme is XKEYSCORE, which sweeps up internet searches, usernames, passwords, emails and documents from around the world. Indeed, 700 servers at 150 sites worldwide are all connected to the NSA’s intelligence analysts.

Information is thus received from the United States but also from Spain, Britain, Nigeria, Mexico, Pakistan, Japan, Australia, you name it. The NSA refers to XKEYSCORE as its “widest reaching” system. And it is not only US intelligence that has access to it: allies such as Canada, Britain and New Zealand do as well and have used it for spying.

All of this is reminiscent of the novel 1984 written by George Orwell, where a “big brother” state has taken control of citizens’ lives. In the meantime, here is a quick guide to close and delete your Yahoo account.

Yahoo says that closing your account is a solution if you “have concerns about your account’s security”.

Indeed, by now, you should.

Julien Mercille is a lecturer at University College Dublin. Twitter: @JulienMercille