If your leg has a mass of 2kg, 1.1×10^10 J of kinetic energy would require your leg to be moving at about 150 100 km/second not faster than the speed of light.

TLDR: Their math is shit.

Chemist (and biochemist) here. Organometallic compounds of Mercury are primarily dangerous because Mercury ions bond fairly strongly to soft ligands like sulfhydryl groups found near the active sites of enzymes. This can result in the displacement of the metal ions or otherwise disrupt the structure needed for enzyme functionality. Mercury metal OTOH is considerably less reactive. It is not safe to breathe in for prolonged periods of time but it is no where near as toxic as its organometallic derivatives are. Dimethyl Mercury for example, is extremely dangerous. A single drop has 100+ times the organomercury content needed to kill someone.

If they knew how to do that they wouldnt be here. https://www.codeproject.com/Tips/5356799/How-to-Place-Mozilla-Firefox-Browser-under-Lockdow

Take out the largest loan I can today, bring that money back to 2014 when bitcoin crashed to 50 bucks each, sell in 2017 when it was around 19k, buy in mid 2019 when it was 10k, hold until it peaked in 2021 and cash out. If you started with 10k and did that, you could be worth over 26 million dollars today. You could be worth even more than that if you managed to leverage more loans and didnt screw up the timeline too much.