This patent plagiarizes prior art. Why does it still exist?

Question

Patent: http://www.google.co.uk/patents/US20070233477

Prior art: http://encode.ru/threads/256-Spec-for-portable-PAQ?p=4703&viewfull=1#post4703

"...The text of the patent is directly plagiarized from this technical report: http://cs.fit.edu/~mmahoney/compression/cs200516.pdf written in 2005 by Matt Mahoney [sic]. The patent application was May 24, 2006..."

One example of a plagiarized paragraph:

"...Until recently the best data compressors were based on PPM, prediction by partial match (Bell, Witten and Cleary 1989) with arithmetic coding of the symbols. In PPM, contexts consisting of suffixes of the history with lengths from 0 up to n (typically 5 to 8 bytes) are mapped to occurrence counts for each symbol in the alphabet. Symbols are assigned probabilities in proportion to their counts. If a count in the n-th order context is zero, then PPM falls back to lower order models until a nonzero probability can be assigned. PPM variants differ mainly in how much code space is reserved at each level for unseen symbols. The best programs use a variant of PPMZ (Bloom 1998) which estimates the "zero frequency" probability adaptively based on a small context..."

Company filing the patent has plagiarised code before: http://www.c10n.info/archives/415

"...The end of their party came on 7th April when Dwing and Johan De Bock figured out that Infima was nothing more than all the major command-line compression tools combined together under a buggy GUI, a massive copyright/gpl violation..."

This patent plagiarizes prior art. Why does it still exist?

Regards.

Answer 1

This "patent" does not "still exist". It never existed as a granted patent. It is a publication of an application for a patent. No patent was granted and this application went abandoned in 2010 (see USPTO Public PAIR). The rejection it got cited Mahoney. Once published, a patent document remains in the databases of patent documents, of course, and serves as a record of what happened when.

Also plagiarism, as such, is not a patent issue. Plagiarism means stealing wording. Patents are concerned with ideas not usually with the specific expression of the ideas in the wording in the specification. Borrowing background information from another patent or other source will generally not have anything to do with patent validity.