I remember in the "old days" that if a referee caught a team playing zone defense that they would blow the whistle to stop the play and call "Illegal Defense".

I haven't seen this foul called in a very long time so I'm not sure if it is because teams have gotten smarter and stopped playing zone or if the rules have been changed.

Also, I have noticed what appears to be a newer foul of "Defensive Three Seconds" where if a defender stands in the lane for 3 seconds then it is a foul giving the opposing team one free throw attempt and the ball back. Is this a replacement rule of some sort?