Are the worms you are seeing similar to this one?
If so, these are bristleworms and are actually beneficial to your in that they will readily consume a lot of organic detritus that may be created in various ways (e.g. uneaten food). I have noticed that they will even consume veggie matter such as a piece of leftover algae/seaweed sheets that might be left untouched by my fish. However, if this is what you are looking at, it is probably best not to touch or pick them up with your bare hand since they can 'sting' you; although, I cannot speak from experience on that one since I just trusted that warning from the day I found them in my tank and inquired about them.
They are also a good source of food for some fish, shrimp, and I believe crabs (arrow crab is the only one I know of off hand though) so they are beneficial in that way as well I guess.
On the other hand though, after both my skimmer breaking on me and my UV bulb burning out, I noticed huge numbers of bristleworms....which it sounds as though you are seeing as well...and in fact, I believe they were partly to blame for my corals suddenly not wanting to remain open until a few hours after my lights came on (I have found that these worms are extremely quick to run once they are illuminated - by a flashlight perhaps). So, after some more research, I realized that the seemingly overabundance of them was my fault because I was providing enough food for them to thrive upon. In fact, I even added a second wrasse to my tank (an 8-line) and both of them couldn't seem to keep up with trying to reduce the population. I also tried bristle worm traps, but the ones I bought also allowed them to escape if I didn't catch them in time - so by morning, they were usually empty. Anyways, point being, if you feel as though you have too many of these bristleworms...if in fact that is what they are...you can help slow that down by reducing the food source via various means (e.g. not overfeeding, remove detritus manually, etc...). In short, they are somewhat like a bacteria or algae bloom in that, without your help, will eat until there is only enough food for a smaller number to survive.
Hope this helps a little bit...and I apologize for rambling on about these worms; while I have known about them for quite some time, I just recently learned more about them when, like I said, I was seeing almost improbable amounts.
P.S. If you cannot tell for certain if your worms match the one in that admittedly bad pic, let me know and I will dig up some more I took a while back...or better yet, try a google or yahoo image search to use as a comparison.
Ive just got a few questions. 
