Since an ad displays instead of a phone number, it sounds like a false positive based on a pattern match in the link. The forum software isnt smart enough to know the difference between a 10 digit number string and a phone number. (possibly even in a 3-3-4 pattern)
I use an email filter at work that blocks SSNs and CC#s when some bonehead doesnt realize email isnt secure and decides to send that info out. We had a vendor that we couldnt reply to because it said his message contained a CC#. Looking closely, his CRM software they use to track messages used an account number that was not only 16 digits long, but coincidentally started with a valid bank # for a MasterCard. Really freaked them out too when we told them about it because they were the same 4 digits as their corporate card. Not sure if it was coincidence or not, but in the end it was nothing.
I use an email filter at work that blocks SSNs and CC#s when some bonehead doesnt realize email isnt secure and decides to send that info out. We had a vendor that we couldnt reply to because it said his message contained a CC#. Looking closely, his CRM software they use to track messages used an account number that was not only 16 digits long, but coincidentally started with a valid bank # for a MasterCard. Really freaked them out too when we told them about it because they were the same 4 digits as their corporate card. Not sure if it was coincidence or not, but in the end it was nothing.