This file can be used to limit the number of activations and requests, which are done through the web interface. It would limit a SPAM attack.
<id>interval</id> Intervall for the unit, defined in type
<value>1</value>
<id>type</id> Type (day, hour, minute)
<value>minute</value>
<id>maxrequests</id> number of allowed requests within the specified time frame
<value>5</value>
You have to activate this feature in the web.config file with the parameter KeyRequestLimitation