Facebook page names must:
Not consist solely of generic terms (e.g., “pizza”);
Use proper, grammatically correct capitalization and may not include all capitals, except for acronyms;
Not include character symbols, such as excessive punctuation and trademark designations;
Not include superfluous descriptions or unnecessary qualifiers;
Not mislead others into thinking it is an official Page of the Page’s subject matter or is authorized by an authorized representative of the Page’s subject matter; and
Not violate someone’s rights
When it comes to tagging other users within an image or a post:
You must not inaccurately tag content or encourage users to inaccurately tag content.
The full list of guidelines for Facebook pages is available here: https://www.facebook.com/page_guidelines.php.
Although Twitter does not have specific limitations in terms of how many people you can follow and how many times you should tweet, Twitter accounts, especially the new ones, are monitored in order to detect any type of automation and excessive activity in order to avoid spam. Here are some of the actions that might be considered as spam:
You have followed and/or unfollowed large amounts of users in a short time period, particularly by automated means (aggressive following or follower churn).
You repeatedly follow and unfollow people, whether to build followers or to garner more attention for your profile.
Your updates consist mainly of links, and not personal updates.
You post duplicate content over multiple accounts or multiple duplicate updates on one account.
You post multiple unrelated updates to a topic using #, trending or popular topic, or promoted trend.
Randomly or aggressively following, favoriting or Retweeting Tweets.
Google+ also allows contents, sweepstakes and promotions to the extent they are permitted by law and as long as they follow Google’s legal terms.
You must have official rules that clearly state that your Promotion is in no way sponsored, endorsed, administered by, or otherwise associated with Google or its affiliates.
YouTube video contests are prohibited on Google+. This includes contests that involve posting videos on YouTube and contests that involve posting YouTube videos on Google+.
Google+ pages are regulated by Google+ Pages Additional Terms of Service, available here: http://www.google.com/+/policy/pagesterm.html.
LinkedIn requires providing accurate information and using real name on profiles. When it comes to profile images on LinkedIn you should not:
Upload a profile image that is not your likeness or a head-shot photo.