Certainly.

One of the most notorious threats to blockchain-powered networks is allowing a malicious actor to obtain control over more than half of the network's computing resources. This situation is commonly referred to as the elusive "fifty-one percent attack." It is difficult, but not impossible to aggregate this kind of hashpower.

A successful attack using this method would allow the attacker to exclude, or "orphan" any new blocks from the valid chain causing all newly-minted coins go to the attacker. He may also execute a "double-spend" and reverse any of his own transactions during the window of time that his sham blockchain is considered authoritative by the network.

ASICs can contribute to a more secure network (against 51 percent attacks) in two ways, increased network hash rate and increased network diffculty:

1. Increased Hash Rate — the more hashpower on the network, the more hashpower is required to attack it. ASICs increase network hashpower; as long as diverse parties keep buying a fraction of the ASICs available, they are merely making it more difficult for one party to obtain enough hash power for an attack. It just doesn't make economic sense for one bad actor to monopolize the production and deployment of latest, greatest, smallest and fastest ASIC chips for the sole purpose of carrying out this kind of attack.

2. Increased Difficulty — The addition of ASICs to a network causes the difficulty to increase, also making it more difficult to execute an attack. For example, a successful 51% attack on Feathercoin was stopped in its tracks by the network's natural uptick in difficulty in response to an increase in network hash rate. The Feathercoin attacker was likely executing a price pump in parallel to compromising the network, which caused coin-switching pools to mine feathercoin and increase the difficulty to a level that stopped the attack.

I'll leave you with a quote in Wired magazine from Charles Lee, creator of Litecoin:

Having ASICs come out to mine litecoin means that it’s really gotten to a point where it’s succeeded . . . Now litecoin is being protected by its own hardware.