Here are a couple of proof-of-concepts... (obviously you need a compliant browser to view this)
HP calculators have always been hackable.
The reason that the 12C / 12C Platinum is allowed on exams (e.g. CFP and CFA Certification Exams, and the GARP FRM Exam) is precisely because they are deemed "not hackable" by the people running the exams.
I guess professors today are a bit more savvy, but when the HP28 first came out and I asked my history professor if I could "bring a calculator" he couldn't see why not
From the article: "Krawetz was also able to determine that the writing on the banner behind al-Zawahiri's head was added to the image afterward. In the second picture above showing the results of the error level analysis, the light clusters on the image indicate areas of the image that were added or changed. The subtitles and logos in the upper right and lower left corners (IntelCenter is an organization that monitors terrorist activity and As-Sahab is the video production branch of al Qaeda) were all added at the same time, while the banner writing was added at a different time, likely around the same time that al-Zawahiri was added, Krawetz says." Why would Al-Qaeda add an IntelCenter logo to their video? Why would IntelCenter add an Al-Qaeda logo? Methinks we have bigger fish to fry than Gonzo and his fired attorneys... }:-) The article contains links to Krawetz's presentation and the source code he used to analyze the photos."