Major UK wireless carrier Three plans to block advertising on mobile devices — and critics are wondering if such a proposal could doom the Internet.

Three unveiled plans earlier this year to block advertising on mobile devices, but now the company is providing more details on their strategy, offering 500,000 of their customers the ability to opt in for this giant test, according to a SlashGear report.

This is a big concern for most websites, particularly media, which rely on ads in order to make any revenue at all. These sites don’t charge a fee, so allowing users to ban ads effectively eliminates this revenue.

Three says they’re going to try to block mobile ads because they say ads count towards customers’ mobile data charges when advertising should be one paying that price.

But Slashgear argues that this goal is counter-productive. If Three is successful in forcing advertisers to stop running ads that customers have to pay to load, then they will have to pay much more for subscriptions to individual websites that would have been free otherwise.

If this campaign is successful, many are wondering what this does to the viability of most free websites, and to the free Internet as a whole.

“We want to improve the experience for our customers with our three principle goals in mobile advertising which we announced in February,” the company said in the statement. “1. That customers should not pay data charges to receive adverts. These costs should be borne by the advertiser. 2. That customers’ privacy and security must be fully protected. Some advertisers use mobile ads to extract and exploit data about customers without their knowledge or consent 3. That customers should be entitled to receive advertising that is relevant and interesting to them, and not to have their data experience in mobile degraded by excessive, intrusive, unwanted or irrelevant adverts.”