Interesting article as it also applies to our hobby.

"Where values increase, the temptation to fake things is obviously greater, particularly with autographs. It's well documented how many fake Muhammed Ali signatures there were in the 90s and 2000s.
Even with decades of experience - including working at Christie's where he helped sell Pele's Brazil shirt from the second-half of the 1970 World Cup final for almost £160,000 - Convery says there are times where help is enlisted from private collectors who specialize in a particular area.
"With such high values, people need to get it correct. That's for sure."