Twitter is a social media platform and is designed for this exact purpose - to allow people to be sociable with each other.
Occasionally, Twitter may lock an account if it appears to be compromised, or if it is in violation of the Twitter Rules or Terms of Service.
This may come in the form of following too aggressively, tweeting too many links, sending too many @tweets etc, the account may be temporarily or permanently locked.
If you find that your account is continually blocked by Twitter - as can often happen when using follow/unfollow software - we advise you may need to reduce the number of actions you take on your account per day.
If you see a message that your account has been locked - temporarily or permanently - follow the instructions in your account to unlock it. Alternatively, you can click here for more information from the Twitter FAQs.