I subscribed to an ical URL:

webcal://ical.mac.com/fthornburg/Fox32Line32up32(Central).ics

It appears that every event in that calendar has an alarm associated with
it. The events are recurrent (it's a TV program).

So, when the calendar was loaded, the alarm daemon proceeded to pop up
reminders, one for each occurrence starting about a year ago. There are
about 3 events per day. The computer quickly stopped responding due to
constant swapping - out of memory due to all the reminder windows.

We need to do something to prevent this from happening. Some possibilities are:

1) Don't show alarms for events that are long past.
2) Allow the user to strip alarms from subscribed calendars.
3) Show only one alarm at a time, allowing the user to "cancel all".