Yes they do!
Use the aluminum standoffs and anchor them with 3/8" concrete anchors. (In the center of the standoff.) You want the anchors long enough to go into the crete at least 2". If they aren't anchored it's dangerous. Wind lift could cause the posts to move, some big fella might fall into one and move it or that dreaded riding mower may take one out if not anchored.
Use the aluminum standoffs and anchor them with 3/8" concrete anchors. (In the center of the standoff.) You want the anchors long enough to go into the crete at least 2". If they aren't anchored it's dangerous. Wind lift could cause the posts to move, some big fella might fall into one and move it or that dreaded riding mower may take one out if not anchored.