I was watching a Fox Sports crawl on TV today that stated that a Philadelphia Phillies baseball fan had been tasered after running onto the field. Shouldn't he have been tased?
If you let the lawyers have their say, both forms are incorrect. Taser is a trademark and as such should only be used attributively; it can't be inflected in any way. They'd probably insist upon "a fan was shocked with a Taser brand electroshock weapon".
In my experience to taze (or is it to tase, possibly in the UK?) appears to be winning out over to taser.
Ron is right, I suppose, but I never take language tips from lawyers.
The company that makes Tasers has said that Taser is a brand name and that the correct word for being hit with one is "tased." I'm sure that the Taser company wants to avoid bad press from people being injured or hit with their item in ways that provide bad PR.
That being said, the English language creates generic trademarks all the time (Band-Aid, Asprin, Zipper, Velcro, Google, Xerox). If a generic trademark is going to be created, the Taser company lawyers probably can't do much to stop it.
I think the key here would be comprehension. There is no clear winner here. A reference to being "tased" or being "tasered" would generally give the same impression to most people and you would be understood with either one.
My personal preference would be for "tasered." I think "Taser" will become a genericized trademark to refer to all electrical powered stun guns and "tasered" will be the word that wins out. But that is just my opinion. I'm sure there are people on here who would disagree with me.
Gramatically speaking, I like the concept that a Taser tases, but I find "He was tasered" to be a nicer sounding sentence than "He was tased". My money's also on "tasered" to win out in the end.