A French Internet company's decision to begin blocking ads for its customers has been derailed by the intervention of Fleur Pellerin, the country's minister of the digital economy, because blocking one form of content -- ads -- could lead ISPs to engage in further censorship.

"This is an initiative that could endanger the survival of a number of economic actors," said Fleur Pellerin on Monday at a press conference covered by Le Monde. "The government should intervene and enact the necessary legislation to ensure Net neutrality because it's a matter of principle."

Free, a French Internet service provider, decided last week to block ads for its subscribers, a decision that denied many websites the ad revenue they rely on to pay for online content.

A firmware update posted last week for the company's Freebox -- a DSL modem, router, Wi-Fi hotspot, network storage device, phone, DVR and IPTV device -- included an "optional ad blocker" to block ads.

However, the update was not optional in opt-in sense. Rather, users had the option to opt-out of ad blocking, because Free had turned ad blocking on by default.

Now, due to regulatory intervention, Free has suspended its ad blocking, ensuring that free content will continue to be available at no charge, at least for the moment.

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Ad blocking remains a difficult subject for companies that depend on online ad revenue. Asked to comment, a Google spokesman in an email said, "We are aware of Free's actions and are investigating." The company declined to clarify its stance on the use of ad blocking software.

Large companies like Google tolerate ad blocking because opposing it risks popularizing it and because most users accept ads. What's more, Google provides tools for publishers to block ads that appear on their websites, because publishers demand control to avoid endorsing products or practices that are anathema to them.

For Google to deny that control to users, particularly after so many years of supporting user choice, would be hypocritical. Moreover, preventing users from blocking ads -- if it were technically feasible -- might open Google to liability for malicious ads, which, although a small percentage of online ads, remain a legitimate security concern.

Nonetheless, some websites try to discourage ad blocking, through prohibitions in their terms of service, technical means or guilt.

Till Faida, co-founder of Adblock Plus, a hugely popular ad blocking plug-in for Web browsers, including Chrome, Firefox and Opera, and (recently) for Android devices, says that trying to block ad blocking software isn't very effective, like any security arms-race.

"Some websites want to block access to people with Adblock Plus," he said in a phone interview. "But it's a community effort. There will always be fast workaround."

Faida says his firm is trying to find a way for Internet users and advertisers to co-exist rather than fight. "It's important that ad blocking is not about destroying advertising," he said. "It's not about censoring content. It's about providing choice to the user."

Faida says that users should be able to determine how much privacy they want and what kind of ads they want. "Our mission is we want to facilitate a middle ground between users annoyed by flashy ads and websites that need to monetize," he said.

His company helps mitigate annoying or intrusive ads by maintaining a whitelist of acceptable ads in conjunction with the Adblock Plus user community. A few large partner companies support the acceptable ads list financially because doing so improves their ad revenue.

Whitelisted ads perform better, Faida insists, generating 15% more clicks in Germany and 5% more clicks in the United States. Coincidentally, these numbers also represent the percentage of Internet users who have installed Adblock Plus: 15% of users in Germany and 5% in the U.S.

The total number of Adblock Plus users is considerable: 43 million worldwide, according to Faida, and growing at a rate of 150,000 daily. And Adblock Plus is not the only ad blocking software out there.