The forums rules clearly state: "All postings to the Forums and their subsequent threads become the property of the Forum owners". Meaning they can do whatever they like with threads or anything else on the site.

We easily forget that this is a commercial site and as forums go, a fair one. Often reasons given for any threads removal might be considered by some to be as transparent as mud and require further explanation. However, the site owners are not obliged to give a reason or justify their actions but [to a point] usually do.

I'm not backing up the site owners, but obviously few members here ever read the forum rules we agree too when we become members and I'm just pointing out an important one.