At one time, my Subscribe to Comments plugin would allow you to have the subscription checkbox checked by default. This is no longer the case. I get a lot of e-mail asking about this change, so I’d like to explain it.
In short, having the box checked by default was causing people to subscribe unwittingly, as it was an opt-out thing. I was getting a lot of flak about this, because a lot of sites had enabled this option without thinking about the ramifications (even I had it enabled for a while!). Opt-out is a bad way to operate, and it doesn’t provide a good user experience. A lot of users see it as being sneaky. Obviously if you want to edit the plugin to re-enable this option, I can’t stop you — but I no longer wanted to be encouraging use of this option.
“But what if you have a user who wants to subscribe to every post?” you ask. Well, here’s how it works now. If you subscribe to an entry’s comments, you’ll get a cookie that remembers that you subscribed. And when you visit other posts, the checkbox will be checked by default (for you only). So you only have to opt-in once. Naturally if you then leave a comment with the box unchecked, your personal default will revert to unchecked. I think this is a much better solution.