'Everybody's Doing It' was the name of a popular revue which opened in the West End in February 1912; the music and lyrics (including a near-eponymous song) were co-written by Irving Berlin. It was also the Manchester Guardian's stab at a contemporary pop cultural reference to describe just how widespread the phantom airship scare had become by the start of March 1913. There are more concrete ways to express this than ragtime. Geography is one; chronology is another.
The graph above shows two things. (After relying on Plot for many years, I've switched to DataGraph, which is not free but is more powerful and much easier to use.) The blue bars represent the number of British periodicals (mostly daily newspapers, London and provincial) which mentioned mystery airships on each day in January-April 1913, while the red bars represent the number which mentioned airships, whether mysterious or non-mysterious (for example, the activities of German or British military dirigibles). It doesn't matter whether a newspaper mentioned scareships once as a humorous aside or devoted half a page to a topic, both are counted equally here. Three phases can immediately be distinguished. (I must admit to having fudged the data a little bit: I've assumed that every issue of the Aeroplane would have mentioned airships, as I don't have access to copies to check. Flight certainly did.) The first, from the start of January through the third week of February, is characterised by a relatively low level of press interest in airships, in which references to mystery airships predominate (though not so much towards the end of this period). The second phase is clearly the peak of the phantom airship scare, the last week of February and the first week of March, when more than two or three times the usual number of periodicals talked about airships, overwhelmingly the mysterious kind. The third phase extends from the second week of March until the end of April. There are far fewer mentions of scareships here, even compared to the first phase. But interestingly, the amount of attention paid to airships in general remains very high: several times that of the first period, and not too far short of that in the second, peak period.