cabbie - 7:26 pm on Feb 8, 2013 (gmt 0)

More likely, I would add a bit of hassle and forward the message to Google.

Don't worry Google are first on my mailing list.

And why exactly are folks supposed to see this a threat?

Well,I wont really be threatening to disavow links.I may include a link to google's blog about disavow links[googlewebmastercentral.blogspot.com ]
And, yes, disavow links will probably not harm their websites anyway...but who knows.

But webmasters should all be on my side.
Most here are taking the angle that you would be losing money in this model :)
Wouldn't you like to get paid for people linking to you?
As MartiniBuster says, whats wrong with asking for a donation to keep the resource upto date and valuable?

BTW, my proposed letter and paypal address was a bit tongue in cheek.I agree some fine tuning needs doing on my letter.
I will probably outsource that to MartiniBuster. :)