Deanna, I’m not entirely sure I understand your question, but there is an important difference between uploading a picture file and uploading a link to an online picture.
If it is a link to a picture on an online service, for example Photobucket, and the file in Photobucket is not shared with the public, then you will be asked to sign in. The ability to see the picture is set at the source; the hyperlink only points to that picture, it does not specifically grant access to it.
Uploading the file, on the other hand, means the file is sent to SpyderLovers, and attached as part of your post. There is no need to link to external storage such as Photobucket.
I’d just advise you to be very careful about sharing files from an online service. At the very least, put the shared files in a separate directory from anything you do NOT want to share.
Let me know if you’d like additional help on this.
Best wishes, Bob