"U.S. energy company Enron, though fundamentally different from tech giants, collapsed in 2001 due to off-balance-sheet debt hidden behind multiple shell companies. Even with proper accounting practices, an increase in joint ventures with low transparency could raise concerns in the market."

Remember the vendor financing model which got a lot of technology companies into trouble at the same time? It took some years, almost all those companies disappeared. Motorola, Nortel, Lucent ...