1- Maybee they sell your personnal photos
2- Maybee you can't delete your account
If you're one of Skype users maybee you know that you can't delete your account , skype is one of programs that don't allow to users to delete their accounts , and if you read the help page of skype they suggest to delete your informations but you don't know if they will keep it on their servers or not .
and Wordpress is another example of websites that don't allow it users to delete their accounts.
3- They can follow you online
4- They can give your informations for legal entities without getting your permission
5- They can stop you from raising any lawsuit against the company
6- Even if you delete your informations they can keep it on their servers