I'm feeling left out...
I'm not sure it's PlusNet's fault for the spam. I've been using plusnet for about 4 years and hardly get any spam at all. I consistently get about 5 spam emails a day and have not seen any increase recently.
I'm very careful about what I do with my email addresses, I have my own domain and so I don't use the actual plusnet account addresses for anything directly, they are just forwarded to from addresses on my own domain. The catch-all address for my domain forwards to a gmail account, not plusnet, so the spam in that account can only be due to randomly generated email addresses being used by spammers, not anything plusnet has or hasn't done.
I did have a spot of bad service from plusnet when I moved house, which lead to me shopping round for an alternative supplier. I couldn't find one that matched plusnet on speed / relyability / features (including the thrown-in hosted stuff like cgi, mysql, php, frontpage etc) oh and cost...
But, if you're an unhappy plusnet user, specially one of those that regularly moans about traffic shaping / p2p file-sharing speeds, then by all means bugger off somewhere else and stop hogging everyone else's bandwidth. You know who you are... Thanks!
Happy PlusNet User :o)