You might want to consider implementing a rule about that similar to Best Change's one:
- Don't spam. Post made after page 5 we usually consider as a spam. We can accept no more than 10% posts of weekly post quota (for example 2-3 of 25), if posts are written after page 5.
There are many kinds of big topics, implementing such a rule might not make sense. Not all large topics are spam.
For example, in the Portuguese tab there is a topic dedicated to books, and another dedicated to movies. These are topics that over time have become big, but it's not spam, because it talks about several books and movies. Let's say it's a mini book or movie club.
I believe that icopress, when giving this alert, is because it must have in mind some topic or some users in specific.