YOU might have noticed that even when using a lightning-fast Internet connection, it takes a few beats, enough time to drum your fingers, for web pages to load. It’s likely because of online advertising, which bogs down your browser, drains your battery and jacks up mobile charges — not to mention collects private data.

So it’s little wonder that the use of ad-blocking software grew 41 percent last year, with 198 million active users worldwide, according to a study conducted by Adobe and PageFair. This represents an existential threat to the $50 billion online advertising industry and has ignited a bitter feud between advertisers and developers of ad-blocking apps. On the sidelines, privacy advocates are pumping their fists for consumer choice while web publishers wring their hands over lost revenue.