If you don’t like what your favorite Internet search engine or e-commerce site does with information it collects about you, your options are limited to living with it or logging off. Major search engines, for instance, all keep records of your searches for weeks, months or even years, often tied to your computer’s Internet address or more. Retailers, meanwhile, generally presume the right to send marketing emails. Although online companies have become better at disclosing data practices, privacy advocates say the services’ stated policies generally don’t give consumers real choice.