"If you have products that people like and they keep coming, you can keep growing," Vestager told a forum at the American Enterprise Institute in Washington.
But she said that when companies become overwhelmingly dominant, "then you get a special responsibility because it is quite obvious that competition suffers if you cont
ol 90 percent of the market." The EU Competition Commissioner said this means a "responsibility not to misuse your muscle."
Vestager's comments follow a decision by EU authorities in June to slap Google with a record 2.4-billion-euro ($2.7 billion) fine for illegally favoring its shopping service in search results.
A year earlier, Vestager shocked the world with an order that iPhone manufacturer Apple repay 13 billion euros ($14 billion) in back taxes in Ireland.
Vestager insisted that her actions were not aimed at punishing successful companies.
"I've never had the run of thinking that we are hammering big companies," she said. "We are punishing illegal behavior."
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