I had a client that also had a pet 'charity' project that we were talked into doing stuff for on a regular basis.
Mostly it was easy stuff that didn't take too much time.
Then he asked me to set up an email newsletter facility so he could keep people updated with events etc. He specifically wanted to be able to send attachments with the newsletter. I set it up and we did a couple of test mailings.
As with everything we do for them, as we don't get paid, the following line is added "this facility is provided by mycompany.com"
Then all hell breaks loose!
Instead of just sending it to their existing supporters some bright spark has the idea to get hold of a mailing list and send it out to 'prospective supporters' (spam victims).
Then to add further insult to injury they attach a 3mb Word.doc!
So countless thousands of people start receiving spam with my company's name on it!!!!!
I declined to do any more work for them