that like click fraud, impressions served to users who use ad blockers are of little to no value to advertisers. Consequently, they argue, eliminating ad blocking would not increase overall ad revenue to content providers in the long run. Business models Tools that help block ads have to work on different business models to stay in operation: Free and open source: Several tools work under a FOSS model, powered by community contributions and donations, e.g. uBlock Origin Whitelisting: Companies have resorted to maintaining a whitelist against a share of the ad revenue to allow "acceptable ads". This has faced criticism, such as Adblock Plus Subscription/Upfront: Some companies in this field have started a subscription or upfront payment model for the tools, e.g. Wipr Freemium: Other companies offer some level of service for free while charge for additional features, e.g. AdGuard Response from publishers Countermeasures Some websites have taken countermeasures against ad blocking software, such as attempting to detect the presence of ad blockers and informing users of their views, or outright preventing users from accessing the content unless they disable the ad blocking software, whitelist the website, or buy an "ad-removal pass". There have been several arguments supporting and opposing the assertion that blocking ads is wrong. Indeed, there is evidence to show that these countermeasures may hurt a website's SEO performance, as users unwilling to turn off their AdBlock, may instead go to a competitor's website listed in the search results. Due to the little amount of time the user spends on the website, and the greater time spent on a competitor's, search engines may view the webpage less favourably and reduce its search ranking. The back-and-forth elevation of technologies used for ad-blocking and countering ad-blocking have been equated to an "ad blocking war" or "arms race" between all parties. It has been suggested that in the European Union, the practice of websites scanning for ad blocking software may run afoul of the E-Privacy Directive. This claim was further validated by IAB Europe's guidelines released in June 2016 stating that there indeed may be a legal issue in ad blocker detection. While some anti-blocking stakeholders have tried to refute this it seems safe to assume that Publishers should follow the guidelines provided by the main Publisher lobby IAB. The joint effort announced by IAB Sweden prior to IAB Europe's guideline on the matter never materialized, and would have most