<p>^^ You can apply ED in two different rounds to two different schools, as one takes place around EA time and the other RD time, but the OP sounded like he/she was talking about concurrently applying ED to two different schools in the same round.</p>
<p>Well you do explicitly sign a contract when you submit the application saying that all is true and you will not apply ED to another school, attending if accepted. If that is not illegal, I am not sure what is</p>