I found out my account with Linode was past due today. How did I notice? The services I have setup on the virtual server I rent from them were unavailable. I logged into the web administration at linode.com and found my account was past due approximately $30.
Shutting down the service is a bit extreme in my opinion. I sent them this feedback:
"Hello, I only discovered my account was past due by my virtual server getting turned off last night. Please make an extra effort to contact me to alert me to the past due issue prior to shutting down the service. That is way too extreme in my opinion. I've been a customer for quite some time and am pretty offended you went to such measures. Please do not do this again."
The account was past due because my credit card on file expired. The same credit card is also used with an account I maintain at Slicehost. Thankfully they sent me several emails to let me know of the issue before shutting down my account!
In all other respects, my experience with Linode has been great.