"In the future, everyone will be anonymous for 15 minutes." So said the artist Banksy, but following the rush to put everything online, from relationship status to holiday destinations, is it really possible to be anonymous - even briefly - in the internet age?

That saying, a twist on Andy Warhol's famous "15 minutes of fame" line, has been interpreted to mean many things by fans and critics alike. But it highlights the real difficulty of keeping anything private in the 21st Century.

"Today, we have more digital devices than ever before and they have more sensors that capture more data about us," says Prof Viktor Mayer-Schoenberger of the Oxford Internet Institute.

And it matters. According to a survey from the recruitment firm Careerbuilder, in the US last year 70% of companies used social media to screen job candidates, and 48% checked the social media activity of current staff.

Also, financial institutions can check social media profiles when deciding whether to hand out loans.

Image caption Is it really possible to be anonymous in the internet age?

Meanwhile, companies create models of buying habits, political views and even use artificial intelligence to gauge future habits based on social media profiles.

One way to try to take control is to delete social media accounts, which some did after the Cambridge Analytica scandal, when 87 million people had their Facebook data secretly harvested for political advertising purposes.

While deleting social media accounts may be the most obvious way to remove personal data, this will not have any impact on data held by other companies.

Fortunately, in some countries the law offers protection.

In the European Union the General Data Protection Regulation (GDPR) includes the "right to be forgotten" - an individual's right to have their personal data removed.

In the UK the that is policed by the Information Commissioner's Office. Last year it received 541 requests to have information removed from search engines, according to data shown to the BBC, up from 425 the year before, and 303 in 2016-17.

The actual figures may be higher as ICO says it often only becomes involved after an initial complaint made to the company that holds the information has been rejected.

But ICO's Suzanne Gordon says it is not clear-cut: "The GDPR has strengthened the rights of people to ask for an organisation to delete their personal data if they believe it is no longer necessary for it to be processed.

"However, this right is not absolute and in some cases must be balanced against other competing rights and interests, for example, freedom of expression."

The "right to be forgotten" shot to prominence in 2014 and led to a wide-range of requests for information to be removed - early ones came from an ex-politician seeking re-election, and a paedophile - but not all have to be accepted.

More Technology of Business

Companies and individuals, that have the money, can hire experts to help them out.

A whole industry is being built around "reputation defence" with firms harnessing technology to remove information - for a price - and bury bad news from search engines, for example.

One such company, Reputation Defender, founded in 2006, says it has a million customers including wealthy individuals, professionals and chief executives. It charges around £5,000 ($5,500) for its basic package.

It uses its own software to alter the results of Google searches about its clients, helping to lower less favourable stories in the results and promote more favourable ones instead.

Image copyright Getty Images Image caption 'Reputation defence' firms aim to remove personal information from public online databases and websites

"The technology focuses on what Google sees as important when indexing websites at the top or bottom of the search results," says Tony McChrystal, managing director.

"Generally, the two major areas Google prioritises are the credibility and authority the web asset has, and how users engage with the search results and the path Google sees each unique individual follow.

"We work to show Google that a greater volume of interest and activity is occurring on sites that we want to promote, whether they're new websites we've created, or established sites which already appear in the [Google results pages], while sites we are seeking to suppress show an overall lower percentage of interest."

The firm sets out to achieve its specified objective within 12 months.

"It's remarkably effective," he adds, "since 92% of people never venture past the first page of Google and more than 99% never go beyond page two."

Prof Mayer-Schoenberger points out that, while reputation defence companies may be effective, "it is hard to understand why only the rich that can afford the help of such experts should benefit and not everyone".

Image copyright Getty Images Image caption Andy Warhol once predicted everyone would be famous for 15 minutes

So can we ever completely get rid of every online trace?

"Simply put, no," says Rob Shavell, co-founder and chief executive of DeleteMe, a subscription service which aims to remove personal information from public online databases, data brokers, and search websites.

"You cannot be completely erased from the internet unless somehow all companies and individuals operating internet services were forced to fundamentally change how they operate.

"Putting in place strong sensible regulation and enforcement to allow consumers to have a say in how their personal information can be gathered, shared, and sold would go a long way to addressing the privacy imbalance we have now."