First, the image from HFT Alert (212,487 Quotes and NO TRADES):
Then the quote fluttering table from HFT Alert Pro (notice at 12:20:38 14K quotes fluttered on the right table and 12:20:40 30K quote bursts registered on the left):
And from NANEX (h/t @BadAlgo):
For more on Preferred share bad algo attacks, refer to this page from Nanex
675 Millisecond view:
225 Millisecond view:
75 Millisecond view:
Themis Trading has tried to warn about this many times, they have their own trove of resources too.