Just the beginning. There are the flags of Sweden, Norway, Denmark, Finland, Iceland, Georgia, the Faroe Islands, Greece, and of ocorse, the UK, England, Northern Ireland, Scotland (But not Wales) and most of the former colonies, Australia, New Zealand etc. that have retained the Union Jack as part of their national flag.
Then there are a few US State flags that have to be changed. Alabama, Florida, Hawaii...
Heaven forbid we should allow anything to offend the followers of Mohammad.