Strange use of poll ...

[Adlago]

I accidentally saw an opportunity to use the html in poll !!!

I am surprised

See a sample poll.

[TSP]

It's been possible to add links and images in polls for every version I'm able to remember. 

It's used in quite a lot of polls on a community I host. 

[Adlago]

Yes, I tested and 3.4.7 - it also has

[TSP]

The usage is for example that you have a poll to vote on the best novel. In which case it's useful with a link to provide the link to read it. Or something like a "Member of the year"-contest where a link to the user profile makes sense. 

As for images; it could be because you'll have an avatar contest or it could be because you have a contest for which image is the best of the month, if someone makes such a contest. In which case seeing the image (could be a clickable thumbnail) is obviously a lot more useful than having options laid out as "Image #2 by Pete" and then you would have to manually find these by browsing some other part of the page. 

Or simply because you want to provide an illustration for a choice or provide more information / background without the member having to look outside of the poll area for external links. 

[Adlago]

This is good. But is there protection for the introduction of malicious links?

[bfarber]

We allow links and images in polls.  This is intended.