Total Internet computational power = 2^{85} operations per year?

I am currently reading the ECRYPT Yearly Report on Algorithms and Keysizes for 2007-08, the last report in this European project started in 2004. The list of authors includes many well-known and respected cryptographers.

A remark on page 14 caught my eye:

In [55] it is estimated that the total computational power of the Internet is about 2^{85} operations per year.

Reference [55] is to another ECRYPT document that mentions the 2^{85} figure without justification or further reference.

Does anyone have any evidence that this 2^{85} figure is true or even approximately correct?