While I get that this is a good idea, it will encourage banks to close accounts of people who've been scammed - they're a risk, right? And run a list of people who've been scammed so other banks know not to open an account for them (although that's probably illegal, but no doubt will happen behind the scenes). Plus the infernal gazillion checks they already run (that probably catch about 0.005% of all scams) will get worse.
Maybe it's a step in the right direction, but I fear the unintended consequences could be worse than the disease.
(Plus people will probably start to say "who cares if it's a scam, the bank will refund me", which is also bad.)
Where's the "I'm seriously conflicted and while I can see both sides of the argument I'm not sure this is the right answer to the right problem" icon?