Many of the tribes monitor the use of their tags. Improper use will get you a downvote. Hopefully, that will help stop the spam tags. I always use one if not two tags to indicate what my content is about.

One problem I see is that may not always agree about what tags are appropriate. I post an Actifit report every day. Generally, I write a short poem about my activity for the day or share a thought on a photo I took while out walking, gardening, etc.

Actifit automatically adds the SPORT tag, I understand the theory that they are tracking steps, but my only connection to that tag is that I actually moved my body during the day! It is not a tag I would have chosen for my posts.