I somewhat agree, but what about it being a string of text and not clickable if the user who posted is below Junior Rank.
That way, we will have user post the link but others will have to copy and paste it, making it secure for everyone.
There are many ways to fight against this issue, I was just making a point which can be further discussed.

I do not think it is necessary also. If you see anything suspicious, immediately you can post under the topic to notify people. If it is more like scam in a way the user want to scam people obviously, just give the user red trust and report it to moderator. Scam is not moderated but there are obvious scam attempt that moderators will delete after you have reported it.
If the link is copy and pasted, I do not think it has much difference because anyone that is foolish for scam will still be foolish, copy and paste the link to proceed.