400% increase in Android malware
I think Rodimus posted it earlier.
I don't think you can infer a 400% increase from that article or it's significance.
Firstly the author made that graph himself and clearly lacks the aptitude to correctly label an x axis, let alone understand the report he was referencing.
The article does not specify if there is a 400% increase in incidence or a 400% increase in malware being used or created, an important difference.
The figures are also not included. An increase of 12 to 48 malware programs is 400%, but an increase of 120 to 480 is far more significant.
Cross platform malware is also not accounted for. The article mentioned WiFi attacks, programs such as Faceniff, which intercept encrypted cookies and can target any OS.
There are multiple antivirus apps available, both paid and free, so there are really no excuses for getting one, nor can you hold google accountable. In fact, it's a recognition of androids popularity that it is targeted by malicious programs.
If you want to reference the issue then you might want to do so directly from the report. The link is provided in the article.