MY hosting account (which includes a few websites) was temporarily disabled a few minutes after updating to Piwik 1.11.1 and playing around with the new Live Map.
Hosting provider (Kualo) thought someone was trying to compromise the website as they registered a spike of 5000+ php calls in a very short time. So the account was disabled for an hour as per their "fair usage" policy.
Here's their comment:
"Unfortunately it may be that this module map is not exceptionally well optimised - looking at your logs it looks as though the vast majority are due to the live api method in piwik."
I've always used the other live modules and never had any resource problems. I'll stop using the map for now until the issue is addressed.
Keywords: Live, resources
5000 calls in 1 hour ? Maybe you had the widget opened in several tabs at the same time?
By default it does a call every 5 seconds (you can change the time by overriding this config setting: https://github.com/piwik/piwik/blob/master/config/global.ini.php#L254 )