Is realvu.com Safe?

Recent event has made me suspicious of sites tacking your activities on the Internet. This is an Internet advertiser and advertisers typically track your activities on the website before you got to the website and what you do after you go to the website. This type of tracking databases can be corseted into giving the government this information as part of the intelligence programs. This is where I become suspicious, I feel like this kind of information should be only available to the legal investigations with a specific warrant issued. Until this right is protected, is it unknown what is going on in the background concerning information.