[CM30]

They also tended to use usergroup permissions to restrict new users from posting URLs before they'd been a member for a certain amount of time (or posted a certain amount of messages) or had early posts subject to moderator approval if a link was included.

Never saw a lot of sites using 'innocent' URLs to sneak porn onto random internet forums in the way you describe, cause said sites would simply treat any spammed link as suspicious regardless of what it claimed to be.