There is already a size restriction in place. From the Forum rules:Because monstrously huge sigs terribly inconvenience our members on dial-up, sig size is restricted in size to 400 pixels by 170 pixels or less. Video sig files are not permitted.
I did find for signatures, not sigs, which is why I didn't find the rule. I do think that a smaller restriction should be considered as 170px is still fairly large in comparison to other images on the board like avatars/icons and there should be a maximum number of graphics/stacking restriction if the current wording doesn't cover it. And I've seen many, many signatures I know exceed 170px or have animations -- not necessarily videos but those animated dragons are just as inconvenient size-wise, especially when there's 12 of them in a single signature. It doesn't seem like this is a heavily moderated concern.
Now that I know there is an official ruling I could start reporting signatures which exceed the 400x170 limitation. From the wording it appears that this is a maximum size limitation so two images which are, say 300x100 stacked on top of each other would exceed the limit because the signature would be 300x200 total.
Could a moderator weigh on if this is correct and 400x170 is a total size limit rather than a per image size limit?
Could a moderator also weigh in on the position on posting multiple animated dragons?
ETA: Yes, I realize that the simple option is just to hide the signatures. I also think, though, that this is the sort of thing that effects more members than just me so while my hiding the signatures fixes the problem for me, sorta (save the fact I'm now hiding the signatures that aren't gigantic and have links to things like blogs and user webpages), it's not going to fix it for the other people who are frustrated by this sort of thing.
But maybe I'm wrong and most people don't care. I don't know. I do think that 400x170 is excessive because of the reality of what if every post on a page in a thread has a 400x170 image? It's not excessive for a single post but it's a matter of being distracting, confusing, etc. when a bunch of people who all have the max (or more) post on the same thread.