I found this post on Consumerist.com from an irate Linux user who can not log in to his Citibank accounts online:

I frequently struggle with Citibank because they seem to have decided to not support Linux and Firefox as clients for their online credit card account management sites.

From some of the comments to the post, it’s not clear that this problem is, in fact, affecting all Linux users. (And on a side note, one of the workarounds suggested is installing the Firefox User Agent Switcher extension that makes Firefox “look like” IE to sites that don’t allow Firefox).

Still, it made me wonder how many Web sites and companies there are out there that make it impossible, or nearly so, for Linux users to do business with them online.

What incompatibility pet peeves do you have with online transactions? Are there other significant companies like Citibank that seem to be behind the curve on serving Linux-based customers?