Shocking news from the Financial Conduct Authority just in. It believes fiddly key pads on mobile devices could cause problems for people who choose to bank in this relatively new manner.
The FCA is worried people will accidentally hit the wrong key and end up transferring £50,000 to an offshore Bahamas account rather than £50 to the man who fixed the garden gate.
You can understand their worry. In the world of financial markets such a blunder is called a "fat finger mistake", one where a trader ends up buying £20m worth of robusta coffee futures when they meant to sell £200,000 worth of frozen concentrated orange juice futures.
It was easier to resolve in the old days on a market floor and the people you needed to plead with were standing next to you.
The FCA said bank customers could be using the apps late at night when concentration wasn't that high, but I think we all know what it really means.
It's no coincidence the number of "fat fingers" in the trading world happen most on a Friday afternoon when traders may have, ahem, imbibed a little.