I'm not trying to distract from the message in this video because it is important. However, using only KJV Bibles is not getting the most out of the biblical lexicology. He brings up a good point to always be wary of the translation. Use multiple sources and use a lexicon to find the original Greek word. In this case the Greek word used in Rev. 13:16 is 'epi' (G1909), which means (1) upon, on, at, by, before (2) of position, on, at, by, over, against (3) to, over, on, at, across, against. This provides greater insight to the meaning. It appears to me that the mark doesn't necessarily mean that it is 'on' the right hand or 'on' their forehead, but it could be 'over', 'across', 'at', 'by', or even 'before' the right hand or their forehead. The three definitions for 'epi' is the word 'on' though. The Greek word 'epi' doesn't specifically state it means 'in' like it does in some versions of the bible. Actually, this provides a better context to the possibilities of what the mark could be. In other words, anything that looks like it could be the mark and should raise the alarm, like we are seeing right now. I don't believe many people will figure it out precisely what it is, until they are confronted with it in a state of duress and terrible oppression.

I wrote some information below that is 'tangential' to the video, but provides a larger scope for the importance of using several sources to understand Scripture.

All Protestant Bibles including the King James is based on the Masoretic Text, which is the work done by the Masoretes in 900 AD. Who are the Masoretes? They are Pharisaic Jews (Pharisees), who recreated a new written 'Hebrew' from Arabic and other existing Canaanitish languages because the original Hebrew was lost in antiquity. The Masoretes used the Greek Septuagint to create a new written 'Hebrew' that had vowel points. Using the Greek Septuagint along with Protestant Bibles provide a better understanding than using just KJV.

The oldest Bible OT there is the Septuagint, which was transliterated from the original Hebrew in circa 285 BC. The original Hebrew written language was becoming extinct. According to tradition, it was Ptolemy Philadelphus, who purchased the freedom of Israelites in his territories, arranged for 6 scholars from each of the 12 tribes to translate the first 5 books of the Old Testament (Pentateuch) from Hebrew into Greek around 285 BC. By this time a practical knowledge of the Hebrew written language was all but lost. The original written Hebrew consisted only of consonants and relied on an oral knowledge to decipher the consonant only words. Think of the 'cat' and remove the vowel. It becomes 'ct'. Without the vowel, the word 'ct' could be cat, cot, cut, cute, etc. An individual of knowledge would be required to orally teach what the word 'ct' was. This is how the Hebrew written language was passed down generation after generation. With the written Hebrew language being dominated by the popular Greek language, which was the world language of the day, Hebrew was in danger of being lost. Ptolemy gathered together 72 scholars and in a short period of time they completed the Pentateuch. The Latin name 'Septuagint' means 70, and was later applied to the translation, for there was approximately 70 translators. This is also the reason why the abbreviation 'LXX' is used for this reason. After the first 5 books were finished, the translators set out to work on the rest of the OT. The exact date this was accomplished is not known, but it is certain the complete OT was finished within 100 years and it is likely it was completed within a few years by the same translators.