I quite often build pages where there’s a link on the page that actually performs an action (rather than just jumps to another page). For example, imagine a list of documents; next to each document you have a *[Delete]* link, which goes to a cgi (passing the document’s ID in the querystring); the CGI deletes the document and redirects back to the page you were on. I never saw any problem with this.
Don’t do this.
It’s all fine, and a nice technique…until you run a spider over the site which follows every link. And then it deletes all the documents. Oops.
A link like this:
<a href="delete.cgi?id=999"><img src="trashcan.gif" alt="[Delete]"></a>