Travel companies have complained to the EU about Google.

This year's early theme of challenges to big tech's power continues: According to the Financial Times, 34 travel firms now contend that Google unfairly promotes its own vacation rental search tool.

• Last year, Google started to display graphic-heavy results from its own rental search tool at the top of search results. If you book via those listings, Google takes a commission.
• Now, companies including Expedia, TripAdvisor and HomeToGo have written to the EU's competition commissioner, arguing that this "favorable" treatment hurts their businesses, because their results now appear lower down the page (unless they pay for ads). They say it's bad for consumers, too.
• The FT says one of the companies, which remains anonymous, has filed a formal complaint with the EU, citing Google's behavior as anticompetitive.
• Google has already received fines totaling €8.2 billion, or around $9 billion, from the EU for giving preferential treatment to its own products. Google is appealing one of those, concerning its shopping business, this week.
• Worth noting: Expedia and TripAdvisor were on the list of 19 complainants for the 2015 case that Google is appealing, so they have history in this kind of fight — one that looks set to become increasingly common this year.