Media companies will be allowed to ban customers who use ad blockers under new online privacy rules proposed by the European Commission. To combat the rise of ad blocking technology, which stops online adverts from showing up on websites, many publishers — including technology magazine Wired and mainstream titles such as Bild, the German tabloid — have opted to ban users who refuse to see advertising. In a proposed reform of the law on Tuesday, the commission attempted to clear up legal confusion by deciding that detection of an ad blocker would not break EU rules.