But then a third-party service spots that change and alerts your bosses. Uh oh.

That’s the scenario LinkedIn has said it is trying to stop being possible. But a judge in San Francisco has just ruled it can do little to stop third-party companies monitoring LinkedIn’s huge trove of data.

LinkedIn must remove any technical limitations it has put in place to prevent the "scraping" of members' data, the court ruled. The BBC understands LinkedIn is considering an appeal.

"We’re disappointed in the court’s ruling," a spokeswoman said.

"This case is not over. We will continue to fight to protect our members' ability to control the information they make available on LinkedIn."

Public data

The case sets an interesting precedent over how the data you publish online can be monitored and used.

The row began in May when LinkedIn sent HiQ Labs a cease and desist letter demanding it stop trawling LinkedIn’s public profiles for data - something that takes place, according to HiQ’s website, roughly every two weeks.

HiQ Labs offers what it describes as "a crystal ball that helps you determine skills gaps or turnover risks months ahead of time, and a platform that shows you how and where to focus your efforts”.

The firm does not monitor every LinkedIn user - just those working for companies that have engaged HiQ Lab’s services. The company told me it also does not offer a service that alerts bosses about an individual's profile changes.

LinkedIn, which is owned by Microsoft, said using its data in this way - to predict when staff might leave - was a breach of the site’s terms of service and also potentially of the US Computer Fraud and Abuse Act (CFAA).

"This is not acceptable,” Linkedin’s letter read.

But HiQ Labs, via a special section of its site set up to discuss the case, has dismissed LinkedIn’s claims of abuse. It said that as the profile information is public, and viewable without being logged in, it should not be “walled off".

"It is important to understand that HiQ doesn’t analyse private sections of LinkedIn,” a spokeswoman for HiQ Labs said via email on Monday.

“We only review public profile information. We don’t republish or sell the data we collect. We only use it as the basis for the valuable analysis we provide to employers.

"Moreover, LinkedIn doesn’t own the data contained in member profiles. It is information the members themselves have decided to display publicly, and it is available to anyone with access to a web browser."

Decades-old law

Judge Edward Chen knocked back LinkedIn’s complaints, citing concerns about restrictions on a free and open internet.

He ruled that the CFAA did not apply as the decades-old law dealt with unauthorised access to closed systems, not publicly available data - and the law's authors could not possibly have envisioned such a scenario when drawing up the bill. (You’ll hear that often - this isn’t the first time an ancient law has been crowbarred into a modern dispute.)

Judge Chen also agreed with HiQ that LinkedIn could hinder competition by blocking the data.

The ruling leaves LinkedIn, and its users, in a tricky spot. The usefulness of LinkedIn is in part due to its data being easy to access. If you’re hunting for a job you naturally want people to be able to find you. But in doing so, you don’t want your information being used in ways you did not anticipate.

That’s what LinkedIn is arguing it is trying to protect, and this ruling makes it hard for users to have one without the other.

LinkedIn does work with third parties to share data and insights, the company told me, but the difference is that it's all within the terms of service members agreed to when they signed up to the site.

In contrast, HiQ Labs, and other third parties like it, use data in ways LinkedIn members have little control over - unless they make their LinkedIn profiles private.