Limit number of visualizations a user can have open at one time

There are cases where a user will attempt to open what is deemed an excessive number of visualizations (or even multiple instances of the same visualization).  The cause of this is irrelevant (could be bad programming on a publicly viewed client, or a mischievous user) but it will actually starve the Web Player of resources for other users.  A configuration that allowed a set maximum number of visualizations that are allowed to be opened by a single user across all Web Player instances would be useful.

For example, if we set this limit to 10, then Bob could open Visualization1 10 times, Visualization1 5 times and Visualization2 5 times, or 10 different visualizations.  However, on the attempt to open an 11th visualization an error would be shown informing the user they have reached their limit and to close open visualizations to continue.

We are actually having this problem with a script that sometimes goes rogue and attempts to open over 100+ instances of a visualization.  While fixing the script is outside the scope of this idea, having a rogue script not starve the Web Player for other users is what should be added.