We may make fun of the Americans all the way long, but recently I found myself in a similar situation. Actually nowadays, 1 kilobyte = 1000 bytes exactly, and to add to the confusion they introduced us a
Kibibyte which will have 1024 bytes.
In December 1998, the IEC addressed these dual definitions of the conventional prefixes by creating unique binary prefixes and prefix symbols to denote multiples of 1024, such as “kibibyte (KiB)”, which exclusively denotes 210 or 1024 bytes. With consistent adoption, this would liberate the standard unit prefixes to unambiguously refer only to their strict decimal definitions, wherein kilobyte would be understood to represent only 1000 bytes. However, adoption by the computer industry has been slow, leaving the exact meaning of a unit ambiguous.
I find the idea rather revolting and I understand the Americans perfectly. To them, thinking that distances are measured in kilometers instead of miles is the same as thinking that there is 1000 bytes in one kilobyte to me. A blasphemy indeed!