Now I like to take part in the odd contest, a flurry of activity to change the experience from regular QSO's in a bid to rack up points and even new dxccs or prefixes, but some contesters take the biscuit.
Apart from the usual 900+ watt power levels, splattering of other callers only 2-5 kHz away either side and finding a station nearly on every frequency on every band, my pet peev (as well as being totally illegal) is the blatant disregard for the band plans and other operators rights to use their mode/calls without undue interference from other stations.
My personal experience has been a recent one, today in fact. Whilst attending a special CASHOTA activation with NCRG on Spike Island, Co. Cork I had checked that my frequency was clear by asking this twice and receiving no reply(although there was tiny splatter from a station 4 kHz above on 7.167/8). I began to operate on 7.163 and had a nice little steady stream of calls going, me giving the information and reference for the award program, and getting nice info in return for approximately 45 mins. Not only was my little pile up picking up pace, but I had a great time telling people about my location etc, when all of a sudden I was totally wiped out by a nearby station, splattering all over my frequency
I turned the dial to see who had wrecked my contacts (as I could no longer hear anyone) only to find a contest station OP0HQ on 7.162! Only 1 kHz away! He obliterated my QSO's as if the bands weren't bad enough.
I decided to call this station and sure enough he answered me in one call which indicated if he could hear me then he knew I was operating next to him. I asked why he had not checked frequencies near him and his answer was that the bands were jammed and he had the frequency since 5am. I pointed out that jammed bands were not my concern and there was no way he could have been occupying that frequency for the past 45 mins as I had operates quite successfully from that time and had the log to prove it. He then retorted that the contest was on and would be finished at 12 which did not concern me in the slightest and I told him so. I couldn't believe the arrogant attitude and self righteousness of his comment and to think his was a HQ station! It really annoyed me if Im honest.
Another issue was the use of other portions of the bands not designated to SSB. I have heard contest stations operating in the CW and beacon portions of the band, not to mention operating outside of bands eg 7.250 just to work the States which is unfair to other hams who abide by their band plans and rules & regs.
Although I won't tar all contesters with the same brush as that would be extremely unfair, but those contesters who don't play by the rules give all contest stations a bad reputation.