This is not scary at all. You must trust any code that you execute on your computer. Pirated games, if they were malicious, can already get whatever they want done on your computer, because you are giving it arbitrary code execution privileges. Fortunately there is a vast network of p2p and scene crackers that are trustworthy, who you can trust (even more so than some publishers) to respect your user rights.

The level of access hardly matters. If you were a malware developer masquerading as a legitimate cracker, there are many privilege escalation tricks you can use once you have any amount of access to a machine. And even if you didn’t, the lowest level of access is typically enough to do financial crimes (stealing browser cookies to access your bank account, or ransoming your documents folder).