Well yes. My forum doesn't hard limit the size of signatures (at least not height), but when you do edit your signature, you will be warned very clearly that your signature is too big in dimensions. In posts, there's also a red box that appears under signatures (and it doesn't add height to the page) that warns if a signature is oversized. It takes a moderator three clicks and no typing to remove a signature and give a reason with an automatic PM.
In addition, there's also a *manual* check for filesize (<=100 KB) on the signature edit page, and I have a script that is run occasionally that removes signature that are too large in filesize.
The automatic dimensions check has so far worked exceptionally well. I haven't seen an oversized signature for a few months. Before, it was a common problem.
