What makes you loose credibility on a web resource?

Modal window asking me to subscribe.

Low contrast between text and background, bonus points if the font is really thin.

Highlighting text does anything other than highlighting text (e.g. opening a menu to share quote on twitter)

Scrollbar highjacking

Clicking on background takes you away from the article (TechCrunch used to do this)

Scrolling down takes you to another article (some news sites do this)

(1) The article is on medium

(2) Pop-over windows (e.g. sign up to our email newsletter)

(3) Ads out of control; not "ads cover content" but "ads cover ads". Many sites like anandtech are designed now so that the pages jitter on mobile in such a way that you try to scroll and somehow an ad gets positioned under your finger and KA-CHING!

(4) Taboolah, Outbrain, anything like that.

(5) "Hiring is Broken", "Does your API need a content marketing strategy?" and other fake memes that are promoted on a pay-for-play basis by Triplebyte, Mulesoft and other information polluters.

Full page takeover popup asking me to sign up for a newsletter. Closed with fist pounding emphasis if I just clicked through on a link from the very newsletter the site wants me to sign up for.

Sites with community moderation and community driven content but advertise as open and free, in which the content and moderation is clearly swayed ideologically.

Asking for payment, e.g. $3/month for a small service, but hiding company details. E.g. in which country the website is operating. Online (e.g. Stripe) payments are simple but I need to know whom I create a contract with.