There was a change at the start of this year. Tax withholding rate is 15% for US residents, 25% otherwise. The brokerage has to file paperwork to verify the account holder is a US resident and so qualifies for the 15% rate. Most brokers did that. If someone is getting 25% tax withheld and is a US resident then it sounds like the brokerage blew off the paperwork. In which case, get a new broker. I'm sure you can find information about this if you look (google).
As for whether anyone should care, you certainly should. Foreign tax credit is limited by various ratios of your foreign to total income, so you may not get it all back.