Which rule did my twitter bot break?

[BeautiCode]

I developed a twitter bot: @postpiratebot . What it does is:

1. Take the note of the top-trending search term on twitter
2. Search for tweets containing the top-trending search term
3. Take the first tweet from the list of tweets, and re-posts it on my page every 15 minutes

What I’ve done to ensure it doesn’t break the rules is:
Remove all references to other twitter users (@'s) including the author
Remove all hash-tags (#'s)

So the bot is now completely harmless, and doesn’t affect any other users.
But my account keeps getting locked because it violates some rule. Which rule is that?

[DanielCHood]

I’d assume this one: https://support.twitter.com/articles/76915

Search “Trending”

Spamming: You may not send automated Tweets or Direct Messages that are spam, or otherwise engage in spamming activity. Some examples of spammy behavior to avoid with automation include:

Trending topics: You may not automatically post about trending topics on Twitter.