These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.
Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.
Your account may automatically post messages containing spammy URLs, be forced to randomly and aggressively follow other accounts and retweet and fav other Tweets.
Your account may gain followers which are fake or compromised.
Your account may be forced to authenticate additional apps.
Your account may accrue large numbers of blocks and become suspended.
If you think you might be using a “free followers” app, review your apps and revoke its access to your account as soon as possible. Learn how to revoke an app here.
