TrackerSmacker ("TS") is the name we've given to our DNS-based ad/tracker blocking service, powered by
The idea is to block hosts that are known to use intrusive tracking methods, which could compromise the anonymity cryptostorm provides.
An example would be visiting a website that's using one of these trackers while on the VPN, then revisiting the same website later while not connected to the VPN (or vice-versa).
The data recorded by the tracking host would allow the website or tracker owner to correlate the data, essentially disclosing your real IP to them even when on the VPN.

Another benefit to blocking ads using this method is that the website won't be able to tell that you're blocking their ads.
With browser addon ad blockers (Adblock Plus, uBlock Origin, etc.), a website can detect that you're using them.
Surely you've seen it on some websites, "Please disable your ad blocker in order to view this content", etc.
Some even go so far as to have that message fill up the whole screen, making that website useless until you disable your ad blocker.
With DNS based blocking, they can't detect it so they can't annoy you about it.

The problem with this feature is that some customers would prefer to do something similar themselves on their own router or system.
Until now, TS wasn't optional. Instead, we were simply disabling it system-wide for about half of our servers, which isn't a very efficient way to do that.

Now, TS is disabled by default. In order to use it, you'll need to use the DNS server when connected to cryptostorm.
For those using the configs from GitHub or hosted here, that means you'll need to add this line to your configs:
dhcp-option DNS
A quick method for adding that line in all your configs would be the commands:
for conf in *.ovpn;do echo 'dhcp-option DNS' >> $conf;done
(while in the same directory as your .ovpn configs)

Those using the widget can enable/disable TS from the Options window in the latest version: