There is a lot of land in Florida and some of it is owned by private individuals and entities and some of it is owned by various governmental agencies. Private owners of land have many rights and generally no one can take the property from them unless they agree to either sell or transfer the property to another person or entity. However, there are a couple exceptions to that rule and one of them is that the government can take all or portions of private property to use for public use through eminent domain.
The government cannot simply take property though, they must have a legitimate public purpose for the land and must compensate the private owners for the land they are taking. There are many public purposes for land though, but there are some restrictions on what the government can do with the land. One of those restrictions is that they cannot take land and then sell it to a private buyer who may be able to generate more tax income through a new development.