As a soon-to-be-regulated financial institution in the UK, we have to be careful who our investors are (and that includes getting into who the LPs our in our investors' funds). It's very easy to take cash, but nobody wants to have that hard conversation with the regulators 6-12 months down the line when they ask you to fully look up your cap table and you realize a quarter of your company is Russian oligarch money / from the middle east / from questionable shell corporations / etc. As regulators around the world get more serious about money laundering, this will become an increasingly important question for venture-backed firms.