BS! They are routinely used to serve “no knock” warrants.
So routinely, in fact, that the Cato Institute has an interactive map of all the incidents where things went wrong using this tactic:
So it didn’t take me long using that resource to find incidents debunking your claim, such as:
Jose Guerena
At 9:30 a.m. on May 5, 2011, officers from the Pima County SWAT team served a warrant on the home of Jose Guerena, an honorably discharged Marine and veteran of two combat tours in Iraq. Pima County SWAT officers approached the Guerena residence and announced the service of a search warrant and sounded a siren. Guerena was asleep after working the night shift at a mine when his wife woke him, saying that she heard noises outside and a that man was at their window. Guerena told his wife to hide in a closet with their 4-year-old son and grabbed an AR-15 rifle. SWAT officers breached the front door and saw Guerena pointing his rifle at them. The officers fired 71 rounds, hitting Guerena with 20 and mortally wounding him. Guerena never disabled his weapon’s safety. The officers retreated from the front of the house and searched neighboring residences that had been hit by bullets that penetrated the far side of the Guerena home. Guerena’s wife, Vanessa, asked emergency operators for help via telephone while police remained outside for approximately 45 minutes. Guerena had been arrested a couple years earlier, but had no criminal convictions and the police found nothing illegal in his home. Guerena’s brother was the primary focus of a drug investigation that brought police to the Guerena residence. The OathKeepers, an organization of current and former military and law enforcement personnel that encourages non-violent disobedience of unlawful orders to infringe on the rights of U.S. citizens, marched in protest of the Guerena raid. Sources: Fernanda Echevarri, SWAT raid fatal drama is revealed in 911 call, Arizona Daily Star, May 14, 2011. Brother of Marine and Iraq War vet killed by Arizona SWAT team was the focus of drug probe, U.K. Daily Mail, June 3, 2011. Hundreds march in protest for Jose Guerena, KVOA.com, May 30, 2011.
What you have here is a tragic situation occurring. As you stated: The Pima County SWAT officers approached the Guerena residence and announced the service of a search warrant and sounded a siren. Unfortunately his wife not he heard that announcement or the siren. The SWAT team breached the residence, unaware that the residents didn't not hear the warnings they supplied, and saw a man pointing a weapon at them. They saw that weapon pointed at them, and responded with deadly force. Remember they are there searching for drugs, and in most cases like these there are bad people willing to fight it out with police. They do not know what becomes known until after the fact.
For you to suggest that this tragic incident is solely the fault of the SWAT team, is ludicrous.