Privacy Policies - A Review
In general, the services I have so far reviewed seem consistent on several points of privacy policy. Firstly, it is a widespread business practice that non-identifying information may be shared without permission. The idea behind this is that it does not actually infringe upon your privacy, as such data is given in large sets and should not reveal anything about any specific person. This is a major way for social networks make money, so it seems understandable.
Secondly, there is a consensus that it is unfeasible to constantly be removing content from caches and backups. This means that your information may linger long after it has been removed. However, this concern is present in any case, as anyone with access to it might conceivably store it for their own use.
Thirdly, as any webserver will log details such as IP address and browser details from users, these services do so as well. Most of the services use these for maintenance/troubleshooting issues, though they are also some of the more relevant information for law enforcement, should they request it from the site. A few of the sites used this for commercial ends, but most did not.
Similarly, you may expect that a website will do anything in its power to try to trace out your exact journey through their service, ostensibly to improve the product.
I would submit that in general a service’s privacy policy makes a very good representation of its activities, mostly because they are obliged to disclose them in some form. For instance, facebook (who, incidentally, had to split its policy across several pages to make it remotely comprehensible) includes in its privacy policy detailed descriptions of how advertisers and partner companies interact with their site. These kinds of details tend to be hidden from the user in normal activity, but play an important role in a user’s assessment of the benefits and risks of using a service.