The floodgates have opened - last week's frenzy of activity, when Expedia and then TripAdvisor submitted complaints to the European Commission about Google, has clearly triggered something.
To paraphrase, as both pretty much argue the same thing, the complaints centre on accusations of unfair practices in search which, the pair argue, is damaging the industry and consumers.
No major surprises there, given that Expedia and TripAdvisor were original members of the FairSearch anti-Google lobbying group in the US.
What raised just a few eyebrows was when, a few hours after TripAdvisor's statement was released, ETTSA (European Technology and Travel Services Association) came out in support of the pair.
ETTSA primarily represents the interests of the GDSs, as well as online travel agencies such as Expedia, Ebookers and Travelocity, in Brussels, but the decision to publicly back individual companies effectively puts the GDSs, under the umbrella of their representative body, also up against Google.
Fast forward a few days and now Amadeus has decided to publicly back Expedia's complaint to the EC.
In a statement issued on its corporate blog, Amadeus says it "shares the same concerns as Expedia" and supports the OTA's decision to run to the EC with an official note of discontent.

"Amadeus does not view Google as a direct competitor to its travel distribution business – whilst Google leads in search, the Amadeus distribution business is focused on providing services and booking capabilities to providers of travel services and travel agents
"For decades travel agents have added value as intermediaries by providing consistent, high-quality and reliable services that allow travellers to find the best value and most appropriate travel solutions from the widest possible range of travel providers."
Amadeus, alongside ETTSA, is particularly concerned about the likely impact of Google Flight Search, when it eventually expands outside of the current customer base of the US.

"It is critical to ensure that Google Flight Search does not mislead consumers into believing that Google offers comprehensive and neutral results, whereas in fact they may be biased, favouring Google’s own services even if they are of a lower quality and an even higher price than other services offered by independent travel distributors.
"It also leads to consumers potentially missing out on the best price available in the market, and limits fair competition between airlines."
So what, some might say, another company complaining about Google?
In recent months there appears to have been a change in the rhetoric, both public and private, from the GDSs when it comes to Google - an interesting switch for anyone watching the development of Google Flight Search, not least how it would expand beyond its launch borders of US-only users.
One of a number of options open to Google was to partner with a GDS to patch up some of the holes in its coverage on the thousands of routes starting and ending outside of North America.
Google vice president for travel (and former CEO of ITA Software) Jeremy Wertheimer hinted at the possibility in November last year when he said introducing Google Flight Search overseas could be made possible by partnerships with "data providers", details of which he refused to disclose at the time.
Sabre's involvement with FairSearch in the US pretty much ruled it out as a likely partner, but Amadeus and Travelport, with their respective airfare pricing engines, were considered viable options, especially with Wertheimer's comments hanging in the air.
ETTSA's statement last week illustrated to some who understand the politics of lobbying in Brussels that the so-called GDS Option appears to have fallen away.
But for Amadeus, which just a few weeks ago saw its UK MD Diana Bouzebiba suggest again that Google needs partners in Europe, to now also come out in support of the anti-Googlers will speak volumes to those that have watched closely ever since June 2010, when Google first announced its acquisition of ITA Software.
Clearly Amadeus is not expecting to be forming a major partnership with Google any time soon. Unless it is some kind of weird reverse psychology, of course.