Sitelock may perform a useful service, but be wary of giving them your credit card information.
When you sign on for the paid service, Sitelock:
1) hides (makes it difficult to find) the fact that they default auto-renew (you can't sign up without agreeing to have them automatically bill your credit card every year);
2) hides (makes it difficult to find) how to stop auto-renew:
a) you can't just stop auto-renew from your billing panel, the way you can with reputable businesses;
b) you have to hunt their web site for a link (in extremely small font) to the page which contains instructions for cancelling;
c) when you get to that page, turns out it's the 5000+ word "Terms of Service" document which you have to scour to find the - get this - PHONE NUMBER - you then have to call and get put on hold (or if you like, they will call you back 3 days later.) Once you finally get through, you have to jump through a lot of security hoops.
All that just to cancel the service.
Their product may or may not be OK, but be forwarned that with Sitelock, it's not easy to get out once you're in.