It is very important for us to provide some data for free users so you may have the possibility to verify coverage and quality before becoming a regular customer. Unfortunately, many malicious users want to abuse the free access to gain large quantities of commercial data for free.
We have enabled a quite complex system to detect malicious and aggressive activities which might span multiple accounts and IP ranges. In such cases we reduce the limit of access for specific users or user groups. This might cause throttling or even blacklisting.
Having a login does usually decrease this effect as it becomes easier for the IDS/IPS team to detect and isolate malicious users.
Interested in the pricing of exploits?
See the underground prices here!