user_block(...) blocks or unblocks a target twitter user.
user_unblock(...) is synonymous to user_block(..., unblock=TRUE).
Usage
user_block(user, unblock = FALSE, token = NULL)
user_unblock(user, token = NULL)
Arguments
user
Character vector of screen names or user ids.
See as_screenname() for more details.
unblock
Logical indicating whether to unblock the intended
friend.
token
Use this to override authentication for
a single API call. In many cases you are better off changing the
default for all calls. See auth_as() for details.