Note that it isn't the greatest to trust random pages on the Internet when importing keys. For example, a bitcointalk.org moderator could replace the above keys with different keys that are all under his control and then post an emergency "urgent upgrade required!" link somewhere pointing to wallet-stealing malware signed by the keys that he placed here.
You could simply sign a message with one of your known public addresses, if you are concerned that a forum moderater could change your post. Sign the whole post (if a signed message that long is possible) or else only sign a message with the PGP keys.
What would that change ? even If we quote him , moderators have the ability to delete our posts. (If not edit them as well - depends on the privileges theymos gave them)