First, don't confuse the Child Online Protection Act (COPA) with the
Children's Online Privacy Protection Act of 1998 (COPPA). The latter is still in effect and requires you to jump through certain hoops if you collect certain data from those under 13 years old.
The former, COPA, was ruled unconstitutional in the past and not enforced, but has now been struck down
in a more permanent way.
While COPA hasn't been a real issue, don't confuse these two similar, but different laws.