Maybe if my bank emailed me, otherwise I doubt it. Local gas stations routinely use $200 holds and I'd have to go way out of my way to see it happen.

The point is whether every user actually notices it, it's that enough of them do that attackers are specifically looking for the ability to do small charges. If you remove that capability, they will look elsewhere.

Yeah… no it wouldn’t. I’ve watched users have their bank accounts emptied (by accident) because they kept refreshing. A measly £150 isn’t going to register until it’s too late anyway.

There's a reason attackers exploit any site that lets them do small charges, it's because enough users will notice a larger charge.

Whether every user notices it or not, attackers are looking for the ability to do small charges, and if you remove that they'll move on.