Why shouldn't we use the (default)src package?

Question

I recently started using Eclipse IDE and have read at a number of places that one shouldn\'t use the default(src) package and create new packages.
I just wanted to know

Answer 1

Using the default package may create namespace collisions. Imagine you're creating a library which contains a MyClass class. Someone uses your library in his project and also has a MyClass class in his default package. What should the compiler do? Package in Java is actually a namespace which fully identifies your project. So it's important to not use the default package in the real world projects.