While owning a trademark may deter some people from copying your brand, it doesn't fully protect against infringement. What a trademark is, is the right for the exclusive use of the mark in commerce, but that right has to be monitored and enforced by you.
If you uncover brand violation, that trademark will significantly extend your options for dealing with it. But to be able to enforce your ownership rights, you first have to know when they are breached. This is why trademark owners should consider trademark monitoring.
You can monitor your trademarks yourself by searching trademark databases, social media and other channels where infringement often occurs. Alternatively, you can sign up for a trademark monitoring service and receive reports via email. Regardless, it is possible to set up a monitoring habit that doesn't take too much of your time and helps protect your brand in the long run.