Very little explanation should be required here.
The
Terms & Conditions are clear:
Originally posted by SimonGray
3.) You will not post links to
images or use avatars and signatures that are offensive, abusive, distruptive and/or hateful. You will
not use avatars or link to images hosted on domains that contain pornography or illegal content.
4.) You will not use profanity in our forums, and will neither post with language or
content that is obscene, sexually oriented, or sexually
suggestive nor link to sites that contain such content. Images of or links to gratuitous gore and/or mutilation are strictly forbidden. This
applies to material posted to collaborative fiction and member short story forums. You will also not select usernames that contain
profanity.

If you can't put it in your
avatar, you can't post it here.
Originally posted by SimonGray
Erotic, Suggestive, Violent or Illegal Content
ATS and BTS is a diverse community with a mission to help people understand important issues from current events and history. Due to an evolution from
women in bathing suits to women wearing less while in suggestive poses that often detracts from the mission, the following content guidelines apply to
the content of both avatars and signatures:
1) No photos of persons wearing less than shirt-and-shorts.
2) No artwork (non-photo) of persons wearing less than bathing attire.
3) No persons, or lnks to persons in a sexually suggestive pose.
5) No persons engaged in what would be considered an obscene gesture.
6) No persons pointing weapons at the viewer of the image.
7) No images or links to images containing blood or gore.
8) No images or links to content containing people involved in an illegal act.
9) No images or links to images containing illegal objects.
10) No images that are taunting in nature toward any person or group of persons.
11) Other content, which at the discretion of forum staff, is designed to be vulgar, obscene, or offensive to the majority of ATS and BTS
visitors and members.

The same compliance is expected with regard to posting images, celebrity or otherwise.
Repeated noncompliance may result in being banned from ATS.