"Browsers keep track of the pages that a user has visited, and they use this information to style anchor elements on a page differently if a user has visited that link before. Most browsers give visited links a different color by default; some web developers rely on the :visited CSS selector to style visited links according to their own preferences.
It is well-known that styling visited links differently from unvisited links opens the door to side-channel attacks that leak the user’s browsing history. One notable attack used window.getComputedStyle and the methods that return a NodeList of HTMLCollection of anchor elements (e.g. document.querySelectorAll, document.getElementsByTagName, etc.) to inspect the styles of each link that was rendered on the page. Once attackers had the style of each link, it was possible to determine whether each link had been visited, leaking sensitive information that should have only been known to the user.
In 2010, browsers implemented a mitigation for this attack: (1) when sites queried link styling, the browser always returned the “unvisited” style, and (2) developers were now limited in what styles could be applied to links. However, these mitigations were complicated for both browsers to implement and web developers to adjust to, and there are proponents of removing these mitigations altogether." https://github.com/explainers-by-googlers/Partitioning-visited-links-history
"The DOGE employees, who are effectively led by White House adviser and billionaire tech CEO Elon Musk, appeared to have their sights set on accessing the NLRB's internal systems. They've said their unit's overall mission is to review agency data for compliance with the new administration's policies and to cut costs and maximize efficiency.
But according to an official whistleblower disclosure shared with Congress and other federal overseers that was obtained by NPR, subsequent interviews with the whistleblower and records of internal communications, technical staff members were alarmed about what DOGE engineers did when they were granted access, particularly when those staffers noticed a spike in data leaving the agency. It's possible that the data included sensitive information on unions, ongoing legal cases and corporate secrets — data that four labor law experts tell NPR should almost never leave the NLRB and that has nothing to do with making the government more efficient or cutting spending.
Meanwhile, according to the disclosure and records of internal communications, members of the DOGE team asked that their activities not be logged on the system and then appeared to try to cover their tracks behind them, turning off monitoring tools and manually deleting records of their access — evasive behavior that several cybersecurity experts interviewed by NPR compared to what criminal or state-sponsored hackers might do."
https://www.npr.org/2025/04/15/nx-s1-5355896/doge-nlrb-elon-musk-spacex-security