I found this page interesting--not sure how long it has been up on the GMAC website.
Apparently so many students are faking their unofficial and official GMAT score reports that GMAC found it necessary to remind B-schools to directly download official scores from the GMAC / Pearson Vue websites!
Business school admission officials might be among the last ones to realize this, but in this era of digital manipulation, you can't trust a PDF unless it comes straight from source: in this case, the test-maker. Of course fake/forged/doctored paper score reports are still around, too, as they have been for decades.
https://www.gmac.com/gmat-other-assessments/accessing-gmat-exam-scores-and-reports/updates-to-unofficial-score-report.aspx